The price of intervention: In a comprehensive briefing paper for politicians and defence experts, Edward Cowan analyses the courses of military action open to the West in former Yugoslavia

SINCE JUNE 1991 the question of outside military intervention in former Yugoslavia has been on the international agenda. While many have examined the case for military intervention, Western governments have been broadly opposed.

1. Political factors for and against intervention

Those who urge military intervention in former Yugoslavia have presented a case based on four themes. First, that the authority of the United Nations has been called into question and should not be seen to fail to halt aggression. Second, that the Muslim world is waiting to see if the Western powers are prepared to defend Muslims, be they Slav or Albanian, against aggressors of Catholic or Orthodox persuasion. Third, that humanitarian concern for innocent civilians demands UN action. Fourth, that unless this conflict is contained it may spread into a wider Balkan war, possibly drawing in Romania, Bulgaria, Greece, Turkey, Hungary and the states of the former Soviet Union.

Those Western governments that maintain a non-interventionist policy have put forward four main reasons. First, that vital Western economic and political interests are not at stake. Second, that military intervention could worsen the situation. Third, that sufficient appropriate defence resources no longer exist for long-term intervention purposes. Fourth, that public support for intervention would evaporate once casualties began to mount. To date, the political will to intervene and then to sustain a military presence in former Yugoslavia has not existed.

However, there are two factors acting against each other that are now causing Western governments to review their policy. The first is that the Vance-Owen negotiations cannot continue indefinitely. The second is the volatile situation in Russia, where nationalist and Communist elements are inhibiting the formulation of a stronger policy within the UN against the Serbs, for fear of creating a pan-Slav alliance posing a renewed threat to stability throughout the Balkans and Eastern Europe.

2. The nature of the conflict in former Yugoslavia

The Serbs, under Slobodan Milosevic, have fought for a Greater Serbia whereby all Serbs within former Yugoslavia would live within their own state. They have exploited their former political dominance in the Yugoslav state and party machine to the full.

The Croats, under Franjo Tudjman, have sought to reassert the dominance of their nation, both within the boundaries of their republic at the expense of the Serb minority and by extension into Bosnia-Herzegovina wherever Croats predominate. They have exploited their ties with Western Europe, and especially with Germany and Austria.

The patchwork nature of the ethnic map, especially in Bosnia-Herzegovina, has made it far easier for Muslim Slavs, but also for Albanian and other minorities, to fall victim to deportation, persecution and genocide on a scale not seen in Europe since the Second World War.

For much of the crisis Western politicians have assumed, incorrectly, that political and military leaders from former Yugoslavia understood the language and conventions of international diplomacy and would abide by negotiated agreements. Except in the Communist period, Yugoslav leaders have consistently demonstrated the reverse, whereby their sense of trickery and intrigue, their own factionalisation and their 'warlord' mentality have predominated, particularly when no internal or external factor existed to enforce compliance.

This has ensured a headlong descent by Serb, Croat and Muslim leaders towards a 'meltdown' similar to that experienced in Lebanon. The eye of the storm is in Bosnia-Herzegovina, but there is potential for further conflict in Croatia's Krajina, eastern and western Slavonia, Sandzak, Kosovo, Vojvodina and Macedonia.

3. The military capabilities of the factions in Bosnia-Herzegovina and adjacent republics

3.1 Serbia/Montenegro - Federal Republic of Yugoslavia (FRY)

On paper, the FRY army remains a formidable force with 20 brigades comprising 100,000 men, 1,000 main battle tanks (MBTs), a similar number of armoured personnel carriers (APCs) and a huge arsenal of towed and self-propelled artillery and mortars. It retains a large pool of reservists among former conscripts.

However, it lacks a strong corps of professional and technically qualified non-commissioned officers, suffers from the constant need to cover the bare essentials of conscript training and carries out little by way of realistic formation manoeuvres at brigade level and above. It is weak in infantry and 'all arms' co-operation.

The air force, comprising 20 front-line ground attack and air defence squadrons, suffers from a high rate of unserviceability and is no match for the technical superiority of Western air forces. Except for shoulder-launched, heat-seeking missiles, army and air force ground-to-air missile and anti-aircraft gun systems would be at a similar disadvantage.

3.2 Bosnian Serbs

The Bosnian Serb army of 70,000 personnel (with further conscripts on call), has retained about 300 tanks (mainly T-55s), 200 APCs and more than 500 artillery pieces from the Yugoslav army. It also depends on heavy-weapon firepower to reduce Muslim towns and villages and capture territory, especially in eastern Bosnia. It has been assisted by irregular forcesin carrying out ethnic clearance in eastern and northern Bosnia, and by artillery support from across the Drina, together with direct infantry and armoured support from the Yugoslav army.

3.3 Bosnian government forces

By contrast, with few material resources, Bosnian government forces have a relatively large infantry force of more than 90,000 personnel based on brigade formations. Their ability to manoeuvre, cross rugged country and press home attacks in strength with the support of artillery and mortars is limited. They have been unable to hold ground when subjected to concerted Serbian pressure, except in Sarajevo.

3.4 Bosnian Croats

The Croatian Defence Council (HVO), operating in northern Bosnia and western Herzegovina as far east as Mostar, is also based on an infantry brigade structure, with as many as 50,000 personnel but with armoured and artillery/mortar support.

3.5 Croatia

The Croatian armed forces, which began the war as an ill-equipped militia in 1991, have developed into an army capable of carrying out limited offensives and holding captured territory. Comprising about 15,000 permanent servicemen and a further 150,000 reservists, the Croats also have a captured inventory of 280 tanks, 200 APCs and some heavy artillery. It is doubtful if their army could sustain an offensive on a wide front against determined Serbian defence in Krajina unless the latter's supply lines were to be cut in northern Bosnia around Brcko. The Croats remain without an effective air force.

3.6 Comment

Throughout the conflict there has been a tendency to over-emphasise the military capabilities of the combatants, and hence to argue that an outside intervention force would be sucked into a 'quagmire'. The FRY's Chief of the General Staff, General Zibota Panic, has told his president that their forces could only sustain resistance against a Western attack for a few days.

This tends to confirm the view that a large-scale, high-intensity operation undertaken by Nato, backed by a sufficiently strong UN mandate, would quickly overwhelm serious resistance by Bosnian Serb forces or those of the FRY, and could be carried out with relatively minor casualties. However, once the longer occupation and low-intensity phase had begun, casualty rates might rise if terrorism and other forms of armed resistance were to take place.

4. Could intervention help achieve a lasting peace?

Intervention itself will not secure a long-lasting peace. It is only an aid to be used in support of a viable peace plan. Such a plan would be one that secures the support of the UN Security Council, which will have due regard for the overall interests of the inhabitants of Bosnia-Herzegovina rather than the narrower political aspirations of the leaders involved in the conflict.

The UN must be prepared to police or impose its chosen peace plan. The use of a large and well-equipped intervention force should obviate the need for fighting to secure the peace other than for local infringements, where negotiation or an ultimatum should suffice.

4.1 The Vance-Owen Plan

Despite earlier agreement in principle to the Vance-Owen plan by the Bosnian Serb parliament, its leaders have continued to object to the plan's attendant map - in particular to province 5, which gives control of much of eastern Bosnia to the Muslims, and also to the absence of a secure corridor to the Serb-dominated province of Banja Luka in the northwest. If subsequent Serbian conquests on the ground lead to a redrawing of the map in their favour, the Muslims would be unlikely to accept since this would bequeath them a ghetto existence in central Bosnia.

4.2 Three-way partition

If the West does not have the will to stabilise a unitary state in Bosnia-Herzegovina, then some argue that it would be better to recognise a three-way split, whereby the Bosnian Serbs would join a Greater Serbia, and the Croats of western Herzegovina and north of Brcko would join Croatia.

This leaves the problem of a rump Muslim state without secure communications to either the Adriatic or the rest of Europe by land. It could also be construed as having rewarded Serbian and, to a lesser extent, Croatian aggression. Overseeing such a split would require a smaller intervention force than required to implement the Vance-Owen plan - the present UN force would probably suffice.

4.3 UN protectorate

The Vance-Owen plan can be criticised for its central idea of 10 provinces, nine of which would be dominated by one or other of the main protagonists and all joined together in a quasi-federal state. But is it reasonable to expect the minorities to live in peace with a Serbian majority intent on their removal? If not, and if the international community is not prepared to accept a three-way partition, then a UN protectorate that dispenses with the province idea, bears examination.

A UN protectorate would aim to rebuild Bosnia-Herzegovina as a genuine multi-ethnic state in which population cleansing would cease, minorities would return to their former homes and lands and each commune or sub-commune would have direct representation to a central parliament in Sarajevo.

The intervention force to underpin a protectorate in the initial stage would be of similar size to that required under the Vance-Owen plan (about 60,000).

5. Is inaction a viable alternative?

The West may continue to waver or be prevented from radical action by Russia, and decide to persist with the present policy of containment through sanctions. If this policy fails, it could result in Serbia incorporating Krajina, eastern and western Slavonia, northern and eastern Bosnia. The situation might then deteriorate in Kosovo and Sandzak, perhaps as early as the end of this year. There is a clear danger of a wider Balkan conflict, although, to some extent, the basing of UN forces in countries around Serbia may help to prevent that eventuality.

6. The objective of an intervention force

This would be to demilitarise Bosnia-Herzegovina to allow the elements of a peace plan to work successfully.

7. The tasks of an intervention force

An intervention force in support of the Vance-Owen plan or of a UN protectorate in Bosnia-Herzegovina would have eight principal tasks:

7.1 Insertion phase

Observe, and where necessary impose, a ceasefire by bringing force to bear on any of the offending parties. This would require the use of ground or air forces, including the enforcement of the air exclusion zone. It could involve attacks across the international borders of Bosnia-Herzegovina.

Create de-militarised zones between and around opposing forces. These would have to be monitored and patrolled principally by UN forces but with forces or observers from the opposing sides.

Open, repair and patrol all main roads and railways that cross front lines and pass through demilitarised zones to ensure the free movement of non-military supplies, humanitarian aid and intervention forces.

Enforce the withdrawal of heavy weapons out of combat range and secure them under UN control.

Monitor the staged withdrawal of all opposing forces back to established bases and then to supervise and ensure their demobilisation.

7.2 Post-insertion phase

Oversee the destruction of all weapons and munitions except those required for a new police force.

Establish this police force on a nationwide basis - at first manned by UN personnel, and then recruit and train a strong multi-ethnic force to help uphold the law throughout the country.

Retain an international force within Bosnia-Herzegovina with further forces on call from outside to guarantee the territorial integrity of this state against outside aggression for as long as required.

8. Composition, source and strength of intervention force

The professional ground forces required in the initial stages would be a combination of light helicopter-borne infantry and artillery units drawn from UK, French, and US air mobile and marine formations. Armoured infantry, armoured reconnaissance, artillery, engineer and logistic units would be drawn from a wider Nato net, including Canadian forces. Former USSR countries might also be involved so long as their forces were of sufficient calibre and were paid directly by the UN.

A two-divisional insertion force consisting of six brigades totalling up to 60,000 personnel should suffice. This force would secure mastery of the ground by drawing on its command of the air, mobility by helicopter, overwhelming firepower directed with accuracy by artillery observation officers and forward air controllers, armoured reconnaissance and infantry fighting vehicles, together with their 'direct fire' weapons and night observation devices.

In the post-insertion phase, strengths might be cut by a third and maybe more. 9. Post-insertion phase

Once a ceasefire had been agreed/imposed, the force required to remain in Bosnia-Herzegovina would need to be sufficient to deal quickly and effectively with any infringements of UN-agreed ceasefire terms. Although, hopefully, the proportion of combat arms could be quickly reduced, engineering troops would be required for longer so as to repair transport routes and public utilities and carry out the removal of minefields and other man-made obstacles.

10. The cost

Precise costings for an intervention operation cannot be calculated, but based on British estimates for its current humanitarian support force in Bosnia-Herzegovina, the costs for one year of the complete intervention force might be as much as pounds 2.5bn. (Based on costs for the current British force of 2,500 personnel for one year announced at pounds 90m. A force of 60,000 with air support would raise costs nearer to pounds 2.5bn.)

11. Conclusions

Nobody doubts that it is in the security interests of the Western nations, working through the UN, to produce a viable political plan which has a reasonable chance of bringing about a lasting peace in former Yugoslavia and prevent the conflict from spreading. Indeed, there is no case for military intervention except in support of such a plan, and any intention to intervene otherwise would be doomed to failure.

The mandate of the intervention force would seek to stop the fighting, to demilitarise Bosnia-Herzegovina and thus to allow the political plan to be implemented. This mandate, and the forces behind it, would need to be sufficiently strong to impose its will on anyone who violates the ceasefire and who impedes progress towards demilitarisation.

In default of such action it might be better for the UN to depart before it is placed in the invidious position of overseeing the Bosnian Muslims being confined to a ghetto existence.

The author, Col Edward Cowan, was trained at Sandhurst and the Army Staff College, Camberley. He saw conflict in Aden, Cyprus and Northern Ireland and from 1987 to 1990 served as British defence attache in Yugoslavia.

This is an abridged version of Briefing Paper No 33, produced by the International Security Information Service (Isis), an independent briefing service for parliamentarians on defence and security services. Copies can be obtained from Stephen Pullinger, Isis, 8 John Adam Street, London WC2N 6EZ.

Andrew Marr returns on Tuesday.

(Photograph omitted)