All-out Balkan war looms after new offensive

The prospect of a Croatian- Serbian war has re-emerged after a year's uneasy stand-off between the states while they waged a proxy war in Bosnia. That fragile balance has been threatened by the three-day Croatian thrust into Krajina. Such a war would involve two recognised nation states, not the war of factions within a third state - Bosnia - which has dominated the news for many months.

The Croatian offensive, unlike much of the Bosnian fighting, had clear strategic objectives: to secure the land link between north Croatia, its capital and the south, including the economically vital Dalmatian coast. Up to 20,000 Croatian troops are reported to have been involved, and with very few of those working in supplies or support, the majority would be fighting infantry.

The UN-protected areas in east Croatia were set up to protect the Serbs there, and Croatian attacks are a further assault on the UN's fragile authority. But under international law, Croatia is a sovereign state, and its forces were operating within it. If they keep their objectives limited, they may get away with it. The Serbs, who have suffered heavily, may let them.

The UN forces in the protected areas are unpopular with the Croats, who want to make it known that renewal of the UN mandate is not guaranteed. They want roads through Krajina reopened and Croatian law re-imposed. If not, they probably now feel strong enough to do without the UN, though they remain wary.

If the Croatian army presses on into Krajina, it may provoke a full- scale Balkan war, compared with which the civil war - or the residual conflict - in Bosnia would be a side-show.

The potential adversaries in a Balkan war are unknown quantities. The forces of Croatia and the rump of the former Yugoslavia - Serbia and Montenegro - have not officially been involved in the war in Bosnia, although many troops and a substantial amount of equipment have crossed the border into Bosnia. Serbian casualties have been heavy, and that makes an up-to-date order of battle difficult to compile.

The order of battle involves two main elements on each side: the regular Croatian (HV) and Yugoslav (JNA) forces, and the militias fighting for their ethnic kin in Bosnia: the Bosnian Croats (HVO and HOS) and Bosnian Serbs (Chetniks, Serbian Guard).

As in the war in Bosnia, the regular Croatian and 'Yugoslav' (Serbian/Montenegrin) forces are about equal in manpower - roughly 100,000 troops each, according to the International Institute for Strategic Studies. On paper, Serbia has 21 'brigades' to Croatia's nine, but the 'brigades' are small units of between 100 and 1,000 troops, and although Serbia officially has a mechanised division headquarters, command and control above these 'brigades' - company- and battalion-sized groups - is probably tenuous.

The Serbian advantage is in equipment and ammunition. The majority of the equipment of the former Yugoslav army was withdrawn into Serbia, and Serbia contains most of the remaining arms factories. Therefore, not only do the Serbs and their Bosnian Serb kin have more equipment: they can also do repairs and keep on cranking out ammunition. So the present UN arms embargo imposed on the area, though widely breached, would favour Serbia.

Serbia's most obvious advantage is in aircraft - nearly 500 fixed-wing and 140 helicopters. These aircraft have hardly been used in the Bosnian conflict, many are probably unfit to fly and the crews, if they exist, are out of practice. If they were to be used, the UN no-fly zone would presumably be enforced by the assembling Western forces - including the British carrier Ark Royal and the French Clemenceau. So that part of the equation can be discounted.

Another imbalance exists at sea, where the Croats have seized most of the naval bases along the Dalmatian coast, while the 'Yugoslavs' only have one. On paper, the Serbs and Montenegrins have many more craft, but their role in any war - especially given the huge international presence assembling in the Adriatic - would be insignificant.

The significant element remains the ground forces. There, the Serbian advantage in heavy weapons is obvious - about five to one in tanks, other armoured vehicles and artillery, though probably still not decisive. Many of the heavy weapons have been destroyed, are unusable, or are already deployed in Bosnia. The International Institute for Strategic Studies said it could not put a figure on how much of the equipment attributed to Croatia and Serbia was already in use in Bosnia, but said it was a lot.

As well as the 100,000-strong Serbian and Croatian armies, the Bosnian Serbs and Croats can probably field up to 60,000 men on each side. The Serbs enjoy an advantage in their favourite weapons: artillery and multiple rocket launchers. The Croats have attempted to build up their stocks; an investigation by the Independent last October indicated they had ordered 10 Czech-built 122mm launchers with 5,000 rockets. These 'Grad' launchers, based on the Soviet BM-21, are the most lethal long-range weapons used in the recent conflicts. The Serbs, on paper, have 200.