STRATFOR.COM Kosovo Crisis - SPECIAL REPORTS
Analysis of Ground Warfare Option
Part I - Introduction
Part II - Operational Doctrine of NATO and Serbia
Part III - Cases and Conclusions
Source URL: http://www.stratfor.com/crisis/kosovo/: Part I, Part II, Part III
Analysis of Ground Warfare Option - Part I
14 Apr 99 1727 GMT
This study is an analysis of some of the aspects of a NATO ground war against Yugoslavia. It does not assume that there will be such an attack. Quite the contrary, we doubt the likelihood or viability of a ground attack. It is useful, however, to analyze the nature of such a ground war, should NATO authorize it. That is the purpose of this analysis. It is not a prediction.
The following study is intended to define the general outlines of such an operation and analyze Serbian military responses. It is focused solely on the military aspects of such a war and includes other aspects only as it affects the military operation. The information is drawn entirely from public sources and includes no classified information of any sort from either side. It operates from the premise that the professional soldiers commanding both armed forces are fully aware of all of these general comments. These reflections will in no way provide advantage to any combatant, who have superior sources of intelligence, deeper experience in warfare and more intimate knowledge of terrain. The primary beneficiary of this report is intended to be the citizens of all combatant countries and it is designed to inform them, in as objective a fashion as possible, of the issues involved in land war in Yugoslavia.
The NATO Mission
NATO has established for itself the mission of compelling Serbia to accept the Rambouillet Accords. This includes the withdrawal of Serb forces from Kosovo Province and Serbias unresisted occupation by NATO Peacekeepers. Serbia has rejected this agreement. NATO has launched an air campaign designed to compel compliance. This has resulted in a massive deportation of Albanians from Kosovo. Therefore NATO demands have now escalated to including the return of all Albanians and has hinted at the inclusion of the separation of all of Kosovo from Serbia. Given the failure of the air campaign, NATO has shifted its focus from an air to a ground war. The declared mission is the conquest of Kosovo province. An implied secondary mission is the fall of the current government in Belgrade and its replacement with a regime more suited to NATOs political ends.
Without achieving the secondary object of replacing the Milosevic government, retaining the primary objective over time becomes substantially more difficult. Serbia will continue to resist the occupation of Kosovo in direct and indirect ways. Therefore, the occupation of Kosovo and its long-term security is eased tremendously if the secondary objective is achieved. In addition, since Serbia can place pressure on other nations bordering it, the loss of Kosovo could result in Serb counter-attacks elsewhere. Therefore, in general, the secondary mission must be of equal importance with the primary mission. From a military standpoint, invading, occupying and administering Kosovo Province in the face of an ongoing Serb military threat is a more difficult and complex task than doing the same having eliminated that threat.
This argues for elevating the secondary mission to a primary position. In most cases, elevating a secondary mission to an equal strategic significance with a primary mission creates the danger of multiple, incompatible strategic goals. This is a rare case in which dual strategic goals simplify matters. The direct approach, the invasion and conquest of Kosovo, poses overwhelming operational challenges in addition to leaving fundamental strategic issues unsettled. This is not to say that the invasion of Serbia and the destruction of the Milosevic regime are militarily feasible. It merely points out that the alternative, simply attacking Kosovo, is less satisfactory.
The difficulties of an invasion of Kosovo province include:
- The invasion would have to be mounted from Albania or Macedonia. Neither of these countries are members of NATO. Macedonia provides the most direct route but it is unclear as to whether Macedonia will permit a multi-divisional force to deploy and attack from its soil.
- There is little to no prepositioned equipment or supplies in this region. This will extend dramatically the time needed to build up an invasion force.
- It is not clear that the Greek port of Thessaloniki will be available for the buildup. Albania lacks ports and infrastructure for the management of complex cargo operations.
- Land transport from Italian ports will require the cooperation of the Slovenian, Bosnian and Croatian governments and movement along roads and railroads vulnerable to Serbian special operations interdiction.
- Land transport from Italian ports will also require access to Montenegro, now part of Yugoslavia and occupied by the Yugoslav Second Army.
- The Serbian Third Army has had months to dig in along the Albanian and Macedonian frontiers and will be difficult to dislodge.
- The terrain makes high quality, high confidence, intelligence gathering extremely difficult. The climate limits the use of optical national technical means of intelligence.
- The terrain in Kosovo is extremely rugged, making armored operations difficult and close air support difficult and dangerous.
- Given the terrain, the likelihood of simultaneously destroying the Serbian Third Army and preventing the development of partisan resistance in the Kosovo countryside is extremely small. The development of guerrilla operations against the occupying NATO force is extremely high so long as the Serbian government maintains its legitimacy and operational control.
- The logistical strains of operating on extended lines inside Kosovo will increase the difficulty of sustaining operational tempo over an extended period of time.
- The probability of substantial casualties in what promises to be a light-infantry operation supported by mobile artillery is extremely high and politically unacceptable.
Therefore, in our view, the limited approach to conquering Kosovo is inappropriate, ineffective and dangerous.
The direct approach is an attack on Belgrade along multiple axes of attack, including south from Hungary, east from Croatia, northeast from Bosnia, and possibly even southwest from Romania. The goal of this operation would be:
- The destruction of the Yugoslavian First Army on the plains west of the Tisa river and north of the Danube.
- The immobilization of Second and Third Armies through air operations and pinning operations on the ground.
- The envelopment of Belgrade, its isolation, and prevention of the escape of the Serbian national command structure from the city to limit the development of partisan operations.
- The capitulation of Belgrade through siege warfare.
- The pacification of the countryside.
- The separation of Kosovo from Serbia in an imposed or negotiated peace.
These are daunting tasks. We will consider three alternative cases in some detail:
Case 1: A limited offensive into Kosovo.
Case 2: A general invasion of Kosovo
Case 3: A general invasion of Serbia
Our judgement is that Case 1 is difficult and dangerous but can, under certain circumstances with extensive resources and preparation, be achieved. We judge Case 2 extraordinarily difficult if not impossible. We judge Case 3 possible only with a major mobilization of forces, the acceptance of substantial casualties on the part of NATO and the probability of an extended occupation and resistance south of the Danube at low and medium intensity for months or longer.
It is our judgement that a ground assault is not a practical option under most reasonable political and strategic assumptions.
Part II - Operational Doctrine of NATO and Serbia
NATOs Operational Doctrine
The United States and NATO have developed a coherent operational doctrine that has, over time, gone under many names. It is, in essence, a highly sequenced, logical and predictable process designed to take advantage of NATOs superior technology and training. It combines extreme fluidity in operations with a highly predictable general sequence. These sequences are:
- NATO operations depend on the establishment of a comprehensive intelligence overview of enemy capabilities, assets, deployments and intention through the use of national technical means of intelligence (satellite imagery, signal intelligence, electronic intelligence) and tactical collection means, including technical military intelligence gathering, special operations and human intelligence. The goal is to have a comprehensive understanding of the structure of the enemys command, control, communications and intelligence structure as soon as possible in order to disrupt its ability to command its forces as early in the conflict as possible. The secondary goal is knowledge of the tactical deployment of key assets, such as aircraft, armor, artillery and above all air defense, so as to permit their rapid liquidation. This encyclopedic intelligence requirement is an indispensable prerequisite for NATO operations. Intelligence denial is therefore a key counter-NATO strategy.
- All NATO operations begin with the establishment of command of the air over the battlefield understood as broadly as possible. Failing command of the air, the goal is sufficient air control to conduct necessary ground attacks in support of the general operational plan. There are three elements in achieving command of the air.
- Destruction of command, control, communications and intelligence facilities needed for the conduct of the air war. This includes radar installations, command facilities, lines of communications
- Destruction of air defense systems, including surface-to-air missiles and anti-aircraft artillery through the destruction of tactical control radar and launch sites.
- Destruction of the enemy air force either on the ground or through air-to-air combat.
- Following initial successes of the Suppression of Enemy Air Defenses Campaign (SEAD), and running in parallel with the continuation and intensification of that campaign, NATO launches more general air attacks on enemy operational capabilities, particularly on ground forces.
- Attacks on strategic transport systems designed to degrade the ability of the enemy to engage in strategic force deployment and supply, pinning or channeling those forces in certain directions.
- Attacks on strategic supply and maintenance depots and mission critical production facilities.
- Attacks on Army, Corps, and Divisional Command and Control nodes.
- This is gradually transformed into attacks on the tactical deployment of forces including attacks on armored formations, artillery emplacements, infantry concentrations and the operational and tactical logistics systems supporting them.
The goal of this air operation is to:
- Disrupt the ability of central command facilities to control operations of deployed units or to gather effective intelligence.
- Limit the ability of enemy forces to engage in strategic redeployment and resupply.
- Disrupt operational and tactical communications and supply systems.
- Destroy unit cohesion and command to the smallest level of granularity possible.
- Impose maximum attrition on all combat assets.
- Disrupt and destroy morale.
As these goals are achieved, the ground attack commences. The primary goal of the attack is the annihilation of the enemys ground forces. The means are strategically defined but operationally fluid combined arms operations. These operations are designed to envelop enemy formations through superior maneuver and intelligence, using tactical air support and armored and mechanized maneuvers. The goal of this maneuver is to place NATO forces in a position to use its fire discipline and fire control systems to destroy enveloped formation through concentrated, annihilating fire.
NATO doctrine is casualty averse and maneuver oriented. The ideal environment is one that permits excellent visibility, has highly maneuverable terrain and is generally free from cities and towns. The worst environment is one in which the climate precludes visibility, the terrain limits maneuver, and which is filled with habitation. Offensive operations in urban environments represent the greatest danger to NATO forces and are to be avoided at all cost.
The goal of the operation is to render enemy armed forces incapable of continued resistance, followed by political capitulation, a negotiated settlement or the imposition of an occupation.
NATO doctrine in summary:
- Recognition that the armed forces of the enemy represent the center of gravity of the enemy regime and that their destruction is the primary mission.
- The use of superior intelligence, maneuver and firepower to achieve the destruction of these forces with minimal casualties to NATO forces.
- Allowing an enemy that recognizes the inevitability of disruption to capitulate.
- Avoiding high intensity conflict in all environments where the effectiveness of intelligence systems, maneuver warfare, and concentrated firepower are at a minimum.
- Avoiding all environments where high rates of attrition are likely to be encountered.
Serbian Operational Doctrine
The modern Yugoslavian Army was constructed to block a Soviet invasion. From its break with Stalin in 1948, Titos Yugoslavia focused its military planning on deterring, surviving and defeating a Soviet attack from Hungary, Romania and Bulgaria. Following tension between Romania and the Soviet Union dating back to the 1960s, Yugoslav thinking saw the primary axis of attack as coming from Hungary, with a secondary thrust from Bulgaria. Given terrain, the Yugoslavs expected the main attack from the north, with secondary operations in the south. The current strategic situation, therefore, is far from novel for Serbian planners. Except for the substitution of NATO forces for Soviet forces, and a threat from Croatia and Bosnia, the Serbs have been thinking and planning for this war since the 1940s. The potential attack from Croatia and Bosnia complicates the strategic problem somewhat less than it might appear at first glance, as we shall see.
Yugoslavia has three goals:
- To preserve, to the extent possible, the Serbian armed forces and particularly the infantry forces. This is an annihilation avoidance strategy.
- To impose the highest level of attrition possible on the occupation force so as to force recalculation behind the occupation strategy. Time is an attrition factor in Yugoslav thinking. Slowing up and tying down forces needed elsewhere is as effective as destroying forces.
- To form alliances with major powers opposed to the occupying power, using the strategic position in Europe and their ability to tie down enemy forces to extract political concessions from either or both sides in the event of a major power conflict.
Yugoslavias experience with Germany defined its planning for a Soviet invasion. That mode of thinking remains in place today. The Serbs draw on the experience of the resistance to the Germans and their planning for the Soviet invasion in their operational planning today.
Yugoslavian operational expectations sequence as follows:
- Yugoslavia seeks to avoid invasion by diplomatic means and through deploying military forces sufficient to deter an attack.
- Failing this, Yugoslavia will initiate conventional resistance to a foreign invasion using armored and mechanized infantry force in border regions. These forces use natural barriers to delay enemy forces and to impose attrition. This is primarily a strategic screening operation designed to cover a retreat of the main force into the rugged interior of the country. In this sense, Yugoslavias armored, air, and naval forces are not considered the center of gravity of the military. It is fully expected and intended that these forces will be lost. The center of gravity of the Yugoslav Army is the infantry formations that are highly mobile, logistically undemanding, and sustainable for extended periods of time in Serbias rugged interior. The main armored and mechanized forces will be annihilated in the early stages of the war. Their mission is to delay their annihilation until the retreat of the infantry is complete and after extracting maximum attrition out of the enemy.
- During the retreat, the goal is to facilitate the link-up of surviving regular Army units with reserve units, irregular militias and newly recruited partisan forces in the interior redoubt. At this point, the Serbs will commence a campaign of extended resistance. This will rely on mobile, light infantry forces coupled with specialized, carefully husbanded, specialized units such as artillery, air-defense systems and so on.
- The key to the success of this plan is a highly robust and survivable command, control, and communications system designed to coordinate disaggregated forces in the interior. The Serbs will seek to take advantage of superior tactical intelligence to bring needed forces to bear in given operations, creating localized superiority, with rapid disaggregation immediately after the operation. In addition, they will use extremely elastic defensive tactics designed to dissipate enemy forces in failed operations. A centerpiece of Serbian operations will be the defeat of the enemys tactical intelligence systems so as to permit their forces to accept or decline combat on Serbian terms.
- Since it is expected that invading forces will be able to co-opt some Yugoslav ethnic groups and factions, operations are expected to become highly complex and political, directed as much at Yugoslav proxies of the invader as against the invader themselves.
Yugoslavian doctrine is based on the principle of extended defense. The first phase of the defense trades conventional forces for time. The second phase uses terrain, climate and tactical intelligence capabilities as massive force multipliers for a mobile infantry force operating from prepositioned reserves and foraging operations at minimal levels of logistical demand for extended periods of time. The goal is to wait for a shift in the external strategic environment. This latter principle worked effectively during World War II but goes back many centuries in Serb strategic thinking.
Part III - Cases and Conclusions
Case 1: NATO Stages a Limited Ground Attack into Kosovo—The Battle of Pagarusa
Circumstances: Unable or unwilling to mount a full-scale invasion of Kosovo or Yugoslavia or unable to wait until a sufficient build-up is in place, NATO decides to mount a limited attack into a region of Kosovo. The mission has two goals. The first is to inflict a punishing blow against the Serbian forces, demonstrating NATO’s ability and willingness to wage effective war on the ground against Serbia. The second is to secure a portion of Kosovo to create a safe haven for returning refugees, either as an international protectorate or as an independent Kosovo Albanian republic. Such a republic would also serve as a rallying point for Albanians to keep them in the region rather than migrating to Western Europe, and threaten Serbia with loss of sovereignty.
Geography: There are currently NATO forces in Macedonia and Albania. The definition of Case 1 is its limited nature. It must be a direct cross-border movement into terrain that is vulnerable to seizure and yet is later defensible. Macedonia has made it clear, thus far that it is unwilling to use its territory for attacks on Serbia. Moreover, Greece has asserted that NATO may not use the port of Thessaloniki to support a ground attack on Serbia. Given these constraints and the limited nature of Case 1, the only practical attack is into Kosovo from Albania. Part of this operation might be an attack on Montenegro, but that would again expand the operation beyond its constraints. A critical issue is how to build up an attack force in Albania, which has no significant port facilities. In a sense, this is the major limiting factor on any attack from Albania. Getting forces in and supporting them in offensive operations will stress Albanian infrastructure tremendously, thereby limiting the offensive force structure.
Terrain: The Kosovo-Albanian border is about 60 miles long. It is extremely rugged terrain, with steep hills and mountains running the entire length. The entire frontier, on both sides, is covered with mountains in excess of 6,000 feet. There are, therefore, no major roads traversing the mountains along the northern half of the frontier. The south is somewhat less mountainous and more developed and has two major roads.
The major road runs from Shkodara in Albania to Prizjen in Kosovo. The road runs along the Drini I Bardhe’s valley, crossing the frontier at Vrbnica. The road runs between two low ridges to the town of Prinzren and from there, along the southeastern portion of the Pagarusa Valley. A second road splits off the first at Kukesi, crosses a bridge over the Liq I Fierzes, then passes through extremely mountainous terrain, crossing the frontier near the Kosovo town of Zub. Another arm of this road runs from Baram Curri to Zogaj, but crossing the border at the same point as the Kukesi-Zub Road. This crossing leads to the town of Dakovica at the northern end of the Pagarusa Valley. In short, there is one mountain road crossing the border and one valley road. Other than that there are only mountain trails. The roads are a little over ten miles apart. These two roads are the only ground attack options from Albania into Kosovo.
This means that the only practical, limited ground attack option under Case 1 is an assault on the Pagarusa Valley. The valley runs parallel to the border, about eight miles along both roads. It then curves northeastward. Inside of Kosovo, a road runs along the base of the hills along the valley’s southern edge, rising into the hills north of Dakovica. That road runs southeast to Prinzen. The valley is ringed on all sides by steep ridges and hills, but there are numerous good roads running north into Kosovo from the valley.
Operations: We recorded the latest Serbian deployment of any reliability about April 13th. The valley contained the 549th Motorized Brigade and the 52nd Light Air Defense Artillery-Rocket Regiment. Obviously this order of battle has shifted of late both because of reinforcements and because of intense NATO air attacks in the region. It is interesting to note that the alleged Serbian attack on Kremica on 13 April did not take advantage of either road, but passed through rugged mountain terrain.
This is will be an essential characteristic of Case 1. NATO forces will be heavily road dependent because of the inherent characteristic of their operations. Serb forces deliberately demonstrated that they are not. This will pose a critical dilemma to NATO forces at all stages of the operation. Clearly, NATO is currently engaged in air operations in this region that is designed to open a Case 1 ground attack option. However, as the Kremica engagement shows, the ability of NATO to destroy armor and artillery using air strikes and Apache helicopters does not completely close off Serbian operational possibilities, so long as light infantry remains intact.
The prerequisite to taking the valley will be the seizure of the mountains on the northwest and southeast side of the valley. Running from Zvegan to the border, with Pec at the base, the Prokletije and Mokra Gora ridges run over 8,000 feet in places. In the southeast, the ridges run over 6,000 feet. Light infantry forces armed with mortars, and infantry packed rockets will be in a position to fire into the valley below. An M74 120-mm mortar is designed as a mountain weapon, capable of being towed on a two-wheeled cart. With rocket assist propulsion (RAP) projectiles, it has a range of about six miles, bringing most of the valley into easy range. Even the Serb’s M69B 81-mm mortar has a range of three miles. Therefore, the valley cannot be taken and held unless the ridges are cleared.
Obviously, this is not a mission for a mechanized force. Nor is it something that can be achieved using air power alone. Indeed, close air support on this terrain is both difficult and dangerous, as man portable anti-air systems are widely available among Serb infantry units. NATO cannot get involved in a light infantry vs. light infantry battle in which it loses all advantage to the defender fully familiar with his terrain. This is NATO’s main dilemma and one that is not clearly or easily soluble except for introducing a large, mixed forced able to carry out multiple missions simultaneously, thereby disrupting and overwhelming resistance.
Without getting into force mix or sequencing, this option obviously means an extended build-up. The problem is that NATO, even in the limited Pagarusa operation, faces four missions:
Given the size of the valley, the multiplicity of missions, and the mix of forces required it is obvious that this mission requires a multi-divisional force to implement. Given that it has taken two weeks to transship 24 Apache helicopters to Albania, it would appear that Albania’s infrastructure, if it could support multi-divisional forces at all, would require a build-up period of at least two months for the shipment of manpower, equipment, and above all, supplies, ranging from petroleum to food. This logistics operation would run concurrently with refugee operations.
- Defending Albania from incursion by Serb infantry at points other than NATO’s attack points. This is also necessary as a defense of lines of supply.
- Seizing the ridges around the Pagarusa valley.
- Seizing the valley floor.
- Holding the Pagarusa against ongoing Serb infantry and artillery harassment.
Case 2: NATO Invades Kosovo
Circumstances: Deciding to enforce the Rambouillet Accords unilaterally and simultaneously return the Albanian refugees to their homes, NATO decides to invade and seize the Province of Kosovo, defend it from Serb counterattack and make it either an independent republic or a province of Albania.
Geography: Kosovo is surrounded by three countries: Albania, Macedonia and Yugoslavia. Both Montenegro and Serbia border Kosovo. A direct attack from Albania alone is extremely difficult to contemplate. Expanding the conquest of the Pagarusa Valley into a general attack creates a logistical dependency on two roads that are vulnerable to harassment and intermittent interdiction by Serbian Special Forces and artillery fire. Moreover, it is not clear that the two roads have sufficient capacity to maintain lines of supply for extended offensive combat by multi-divisional NATO forces operating at substantial distance from base. Finally, Albania lacks the port facilities needed to stage a substantial invasion of Kosovo.
Indeed, the key problem of any invasion of Kosovo is logistical. Albania is separated from both Bosnia and Croatia by the Montenegran republic of Yugoslavia. That means that land transport by rail or road into Albania is impossible without the prior conquest of Montenegro or the expulsion of the Yugoslav Second Army from Montenegro by internal unrest. We regard that outcome as extremely unlikely. Thus, it is impossible to move European-based NATO forces into position to attack Kosovo by land. This makes the Italian ports useless for a Kosovo invasion. The only alternative is access to the Greek port of Thessaloniki. The Greek government, however, has made it clear that it will not permit the use of Thessaloniki in support of a ground war against Serbia.
An additional consideration is the matter of Macedonia. An attack from Albania alone is unlikely to succeed. An attack supported from Macedonia has a better chance of success by permitting two fronts. However, the Macedonian government is adamantly opposed to the use of its soil for mounting an invasion of Kosovo, particularly one which might leave the Serb government intact and looking for revenge. The Macedonians are caught between Serbia and Greece, neither of which would look kindly on Macedonian participation in an invasion of Kosovo.
Finally, even an attack from both Albania and Macedonia suffers from the same core defect: too few roads through extremely bad terrain from which to support a multidivisional force in offensive, potentially high intensity conflict. In order to invade Kosovo, it is essential that NATO first seize Montenegro. From Montenegro, an attack east into Kosovo along a more robust road system is possible. That would allow a three-pronged attack into Kosovo that might succeed.
However, we have already violated the principle of Case 2, by positing a prior expansion of the war to Montenegro. Having seized Montenegro, an overland route to Albania and Macedonia would exist. But that would mean first a build-up in Croatia and Bosnia for an invasion of Montenegro; the successful defeat of the Second Army; repair of wrecked transport facilities; a build-up in Albania and possibly Macedonia; and finally the invasion of Kosovo.
In all of these senses, we regard Case 2 as impractical.
Conclusion: Geography makes an invasion of Kosovo impossible without an invasion of Montenegro. That would mean that NATO would be engaged with both the Serb Second and Third Armies. Under that circumstance, Case 2 would have become a general war with Yugoslavia rather than a limited conflict on the order of the conquest of the Kuwaiti salient. Thus, Case 2 forces us to consider Case 3, a general invasion of Yugoslavia.
- Case 2 presupposes a prior attack on Montenegro which violates the logic of the case in the first place and massively complicates the problem.
- There are no available port facilities for building up a multidivisional force in Albania.
- An attack from Albania cannot be sustained logistically.
- Macedonia is unwilling to permit an attack from its soil and its own cross- border road system is limited.
- There are no port facilities available for sustaining ground combat from Macedonia unless the Greeks reverse their position.
Case 3: The Invasion of Yugoslavia
Circumstance: NATO has determined that it must invade and occupy Yugoslavia. One motivation might be that it is impossible to seize all of Kosovo without engaging the entire Yugoslav Army. Another motivation might be the sense that without the overthrow of the Milosevic government, NATO’s goals cannot be achieved. Therefore, NATO orders the invasion and occupation of Serbia.
Geography: Serbia can be attacked from all directions. On the surface, this would appear to put it in a hopeless position. However, the situation is more complex than it appears.
Five potential invasion routes exist:
It is important to note that even a simultaneous attack on all these fronts, should it be mounted, would not undermine the core Serb strategy. The area south of Belgrade, west of the Marava river, north of Kosovo and east of Montenegro, around the towns of Kragujevac and Krajlevo, is the redoubt in which Serbian resistance will form, even assuming that Montenegro, Kosovo and Vojvodina are lost. There is no rapid entry into that region.
- From Hungary into Vojvodina toward the Danube
- From Croatia and Bosnia east toward Belgrade through the Danube and Sava Valleys.
- Romania west through the Danube valley toward Belgrade
- Albania-Macedonia north into Kosovo
- Bulgaria toward Bor and Nis
But there are deeper issues.
Operational Geography and Terrain: A thrust south from Hungary would be designed to reach and breach the Danube river, capture Belgrade and Novi Sad, and permit the rapid penetration of the interior by NATO forces. The direct route is down the Tisa river valley, with the eastern bank the most natural line of attack. There are several problems with an attack down the east bank of the Tisa. First, the gap between the river and the Romanian border at the Hungarian-Serbian frontier is barely more than ten miles wide. Unless the Romanians gave permission for NATO forces to enter their territory, the possibility of being delayed at the border by minefields and Serb armor and anti-tank infantry would be substantial. Moreover, as one proceeds down the Tisa river on the east bank, the ground becomes marshy and poses problems for Infantry Fighting Vehicles. Finally, the town of Zrenjanin is strategically located on several roads and must be taken to approach Belgrade from that direction.
- The main line of attack would come from Hungary. However, Hungary has no contiguous border with any other NATO country. A buildup in Hungary would have to pass through either Austria or Slovakia. Austria has historically avoided NATO issues and is terrified of refugees. An invasion from Hungary would generate hundreds of thousands or millions of Serb refugees who would pour into Hungary and Romania. They would inevitably find their way to Vienna. Since refugees are one of the hottest issues in Austrian politics, Austria will not support any action that would generate more. Slovakia remains interested in entering NATO. It is also a Slavic country with factions that have close ties to Russia. Tremendous Russian pressure would come to bear on Slovakia. We are not convinced that a buildup in Hungary is possible.
- An alternative route of supplies for Hungary, and supporting Bosnia and Croatia as well, would be Slovenia. However, Slovenia has no ports. This would require the use of Italian ports. The Italians are deeply uneasy about the air war. A ground war based on Italian logistics could bring down the government. Moreover, while the U.S. already maintains substantial forces in Tuzla in Bosnia, that infrastructure is already strained and would have to be reinforced dramatically before further forces are introduced. The situation is even worse in Croatia.
- A buildup in Albania for a limited operation in Kosovo is possible. However, the terrain and port facilities are such that major additional logistical forces would have to be introduced and these would compete with refugee support.
- Macedonia has declared that it would not permit its territory to be used against Serbia. Moreover, it would be impossible to conduct a major buildup in Macedonia without Greek permission to use the port of Thessaloniki. The Greeks have indicated that they would not permit this.
- If building up forces in Hungary is complex, introducing forces into Romania and Bulgaria would be logistically, politically and diplomatically nightmarish.
The approach down the western bank is more promising, with flat land, excellent roads and multiple approaches from the Tisa to the town of Sombor. Moreover, the attack can be supported out of Vukovar in Croatia. Such an attack will certainly annihilate Serb forces north of the Danube. The problem is that the Danube river would not be breached. The Danube, between the town of Novi Sad and the Croatian border poses a particular problem. Apart from being a formidable barrier in its own right, the southern bank of the Danube is elevated and, at certain points, consists of cliffs. Thus, the defenders on the south side of the Danube hold the high ground and can pour fire down on bridging forces.
Morever, a general advance to the Danube would have to wheel east to take the town of Novi Sad and then, if it intended to approach Belgrade, would have to cross the Tisa river. Thus, A relatively small Serb force between the Tisa and the Romanian border could both prevent an attack on the east bank and then move into position as a blocking force for cross-Tisa operations.
A solution might be an attack out of Croatia between the Danube and Sava rivers, designed to take the Danubian heights from the rear. The problem is that the terrain of such an advance passes through low hills with limited roads. The advance could not keep up with the speed of the armored thrust to the Danube. It would be an infantry force completely out of synch with the armor.
All of this, of course brings us to the core question: Belgrade. Belgrade is located at the confluence of the Sava and the Danube. It is densely populated with extensive construction and substantial suburbs. Worse, it rests on hills on the southern side of the Danube. Attacking it directly is an impossibility. It poses the classic problem of urban warfare to a mobile force. It is to be avoided at all costs. But Belgrade cannot be avoided. Access to the road systems into southern Serbia require that Belgrade be at least placed under siege if not attacked directly.
There are two models for taking Belgrade. One is the Berlin model. There, Soviet forces with complete air superiority, superbly trained infantry and armor, massed artillery, attacked a city defended by untrained and poorly armed youngsters and old men. The Soviet Army took 300,000 casualties in less than a week’s fighting. The other model is again drawn from the Soviets: the conquest of Budapest. There, rather than entering the city, the Soviets surrounded it and bombarded it with artillery and aircraft for six weeks until the city capitulated.
In order to invest Belgrade, a force will have to move east along the southern bank of the Sava river. That force would logically be the 10th Mountain Division that the U.S. currently has positioned at Tuzla in Bosnia. Unfortunately, the logical route it would take passes through Bjijelnjia, which is currently occupied by a Russian brigade. Secondary routes are available but would extend operational time dramatically.
With the fall of Belgrade, the real war would begin. NATO forces would then face the need to move south into terrain populated by hills ranging from 500 feet to more than 2000 feet in very narrow valleys, heavy foliage in summer, poor roads and a hostile population.
The terrain argues against an attack on Serbia. A direct attack designed to seize all of Kosovo is dependent on Greek cooperation. An attack to seize a limited portion along the frontier does not require more than Albanian cooperation and will probably not be heavily resisted by the Serbs.
An attack designed to conquer Serbia is possible. However, it presents massive problems of strategic geography and operational terrain that have made it an extremely daunting task. Moreover, given Serbian operational principles, the main thrust of the attack north of the Danube plays directly into Serbian hands by given them time to retreat into the south. Since no rapid penetration and seizure of the area south of the Sava is possible except with a massive occupation force prepared to accept substantial casualties, the geography and terrain presents the first and most significant challenge to any attack.
Forces Required: The first phase of the operation would require primarily armored and mechanized forces. Given that the screening force north of the Danube would have been heavily damaged by NATO air strikes, the movement from Hungary to the Danube could be executed efficiently. Given the frontage and follow-on missions anticipated, this would still require at least two armored divisions. The strike from Croatia would require a third division, while the attack out of Bosnia would require an infantry division, preferably mountain.
This four division force would needed to be rotated into reserve for maintenance and replenishment while Belgrade was placed under seize by suitable forces, heavily weighted toward artillery designed to reduce resistance in Belgrade. Thus, a reasonable assumption would be that the conquest of northern Yugoslavia, including Belgrade and Novi Sad would require five divisions plus support elements. In addition, if we assume that a secondary thrust into Montenegro was planned, this would consist of at least two divisions with a third in reserve.
Finally, and most importantly, forces would have to be made available to enter Serbia south of the Danube, preferably before Belgrade capitulated, in order to disrupt the withdrawal and deployment of Serb forces into the central mountains. The preemptory establishment of strategic fire bases throughout the area will require at least two infantry divisions with heavy artillery and an air mobile division to provide a mobile attack capability, in addition to light infantry to engage the Serbs. We would calculate a four-division requirement.
Additionally, the equivalent of two divisions would have to be deployed in defensive positions in Albania and Macedonia in order to prevent Serb counteraction in those areas.
In short, we estimate that a force of twelve divisions with full logistical and other support would be needed for a successful invasion.
The build-up period for this invasion would require at least four months, assuming that the Germans were prepared to carry the bulk of armored operations out of Hungary. If the United States and the United Kingdom were to assume this burden, the preparation time for the invasion would expand to well over six months.
We have examined three cases of ground combat against Serbia by NATO. Each of these cases provides extremely difficult battle problems.
In our view, NATO does not have acceptable ground combat options against Serbia.
- Case 1 is a multi-divisional thrust designed to seize a small part of Kosovo. It poses severe logistical problems with an extremely large force required to seize a very small portion of Kosovo. The possibility of long-term combat and attrition is high. This is the most doable of the options.
- Case 2, the direct invasion of Kosovo, is impossible due to geographical realities compounded by terrain.
- Case 3, the invasion and conquest of Serbia, requires a massive mobilization and deployment of NATO’s resources and extended combat. It opens the United States to vulnerabilities elsewhere in the world, particularly in the Persian Gulf and Korea. It is not clear that even a ten-division force could subdue the Serbs in their redoubt. However, short of complete pacification, this is a militarily viable option, allowing for resource expenditures, extended duration, casualties and geopolitical complications with Russia and elsewhere.