Until now, Serb-held territory in western Bosnia and in southern Croatia was cut off from Serbia proper by Croat-held and Bosnian-held territory. Now, the Serbs hold a swathe of territory - from Knin in Croatia, through Derventa in Bosnia, to Belgrade.
The Slav Muslims are the largest single ethnic group in Bosnia- Herzegovina. But, with the Serbian gains and recent Croat victories, they scarcely control any territory outside Sarajevo. Instead, the Serbs and the Croats have carved up the territory.
This week, the Croats declared a separate state ('Herceg-Bosnia') in the south, to the fury of the Bosnian leadership. Yesterday, the Serbian leader in Bosnia, Radovan Karadzic, issued the call the Bosnians had dreaded: that Serbs and Croats should now partition Bosnia.
Croat politicians - who have in past months lied almost as cynically as their Serbian counterparts - have consistently denied plans for such a carve-up. President Franjo Tudjman has talked of Bosnia 'within its historic borders'.
The proposed confederation - in effect, an annexation of Bosnian territory - may eventually become real, because of the combined clout of the Serbs and Croats. But they, unlike the Muslims, have shown no enthusiasm for mutual tolerance of different ethnic groups. Thus, the territorial gains by Serbs and Croats alike will only increase the long- term instability of the area.