For the fourth successive day, Yugoslav forces and guerrilla units of the Kosovo Liberation Army (KLA) exchanged fire yesterday across the rugged frontier region of Tropoje, almost 200 miles north of the Albanian capital, Tirana. The Yugoslav authorities claimed last night to have killed 150 "terrorists" who were trying to re-enter Kosovo, but Albanian and international officials put the death toll at seven; four KLA fighters and three Albanian citizens. One journalist was also wounded.
In purely military terms the Serb attacks, using machine- guns and mortar, are no more than a variant - albeit a fiercer one - of the "hot pursuit" tactics employed in earlier phases of the Kosovo crisis against KLA insurgents operating out of villages and bases on the other side of the frontier.
Now, however, any remaining fig leaf of Albania's neutrality in the face of the devastations visited upon the Albanians of Kosovo has vanished. Last night, as witnesses in the area reported continuing heavy explosions, Tirana cast in its lot totally with the alliance, calling on Nato to send its aircraft and missiles against the Yugoslav artillery positions responsible for the shelling.
Albania, moreover, is both the hub of the humanitarian effort to help the refugees and the almost-certain launch pad for any ground war. Tirana's weekend announcement that it was ceding control to Nato of its ports, airspace and other military infrastructure underlined the point.
What is more surprising is that the fighting has not yet spread to three other neighbours of Serbia - although there is absolutely no guarantee that it will not do so if Belgrade ups the stakes further, or if the ground war that Nato still rules out begins to look inevitable.
The first of the feared explosions that have not yet materialised is Bosnia where, contrary to many expectations, ethnic Serbs have not gone on the attack against the Nato forces preserving an uneasy peace in the country since the Dayton accords of 1995.
Equally precarious, but still outside the war, is Macedonia, the base for 12,000 Nato troops who in happier circumstances were meant to lead the international peace-keeping force for a post-settlement Kosovo. In retrospect, the key to Macedonia's relative stability is the deed for which 10 days ago it was most bitterly criticised: the forced onward expulsion to Albania and elsewhere of the tens of thousands of refugees who had fled there from the Serb terror.
Although the step certainly compounded the appalling human suffering of the Kosovo Albanians, it may well have averted a showdown between Macedonia's Slav majority and its large and restive Albanian minority, creating in effect a second Kosovo - but with 12,000 Nato troops caught in the middle. Indeed, that showdown could yet come, should the Nato force enter Kosovo against the wishes of President Milosevic.
But most precarious in the Balkan domino chain is probably Montenegro, Serbia's junior - and last remaining - partner republic in the Yugoslav federation. The war has brought strains between the reformist, Westernising government of Milo Djukanovic, which took power last year, and the pro- Milosevic opposition, backed by the Yugoslav army, to breaking point.
Mr Djukanovic has warned of a civil war if Belgrade tried to foment a coup against him. Yesterday's news that the Yugoslav parliament had voted to join a "Slav Union" with Russia and Belarus only brings that prospect nearer.
Of itself, the union does not represent much of a step towards the spectre of the wider European war that the Russian President, Boris Yeltsin, was brandishing last week. It contains no provision for mutual defence, or even economic aid. At best, it is a symbolic gesture of solidarity which left even Russia lukewarm.
But for Montenegro it could be the litmus test. The socialist old guard will demand that it assents to the union. But even before the vote in Belgrade, senior Montenegrin officials were insisting the republic's future lay in the European Union and Nato's Partnership for Peace, rather than - as one supporter of Mr Djukanovic put it - in a recourse to "myths" and "Orthodox fundamentalism".
Meanwhile, Greece, the Balkans' richest Orthodox nation, still manages to walk the tightrope between Nato membership and a deep instinctive and historical sympathy for Serbia, its ally against the Turks in Balkan conflicts past.
But there, too, tensions are growing. Greeks have long held Albanians responsible for the country's growing crime problem. Now there are reports of frightened Albanian workers returning home after death threats from Greek nationalist extremists, linked to the Orthodox church.Reuse content