The show of military resolve to defend the remaining Serb territory of eastern Slavonia was intended to warn the Croats and to soothe Serbian public opinion.
"It all depends on Croatia," said Vladislav Jovanovic, the rump Yugoslav foreign minister. Croatia has told the United Nations it will not open a new front in Eastern Slavonia. But large forces are ranged against each other and artillery exchanges take place regularly. Mr Jovanovic said Serbia would have no choice but to fight if its "vital interests" were jeopardised.
Such statements are, no doubt, intended to reinforce a battered national pride. But yesterday's flood of refugees dented any pride that Serbs might muster in the still formidable array of Soviet-era weaponry deployed across the flat farmlands. The latest arrivals, driving smashed-up cars and bringing tales of violent humiliation at the hands of the Croats, have swollen the numbers of embittered refugees sent forth by the collapse of the Krajina.
President Slobodan Milosevic of Serbia, the arch-nationalist turned peace- maker, must now be engaged in a three-way fight to retain his command over the country's political direction. First he sorely needs to reassure public opinion, a task partly fulfilled by his successful visit to Moscow yesterday which won a pledge of support from Boris Yeltsin and the prospect that Russia will unilaterally lift sanctions on Serbia.
That move would help ease Mr Milosevic's second objective, the containment of the Krajina Serb hordes descending on Serbia. Their needs will further weaken Serbia's half-strangled economy, with unpredictable political results. Russian aid would demonstrate Pan-Slav solidarity, maintain Mr Milosevic's credentials as a shrewd leader and defuse the wild talk of betrayal and vengeance circulating among Serb radicals.
The radicals held a rally late on Wednesday in Belgrade's Republika Square at which up to 10,000 people shouted for vengeance. A prominent Orthodox clergyman, Metropolitan Amfilohije Radovic, told the crowd that "the Belgrade leadership" was most to blame for the fall of Krajina.
These excitable sentiments no doubt remind Mr Milosevic of his third problem - the one that will be central to any settlement. That is the intractable behaviour of the Bosnian Serbs, whose military and political wings seem locked in an unresolved schism between Radovan Karadzic and General Ratko Mladic. Mr Karadzic, struggling to boost Bosnian Serb morale, toured the front-line town of Bosanski Novi yesterday, and appealed to the remaining residents not to abandon their homes.
Well-informed sources in Belgrade say that Mr Milosevic has done all he can to strengthen General Mladic, with assistance on military hardware,logistics and intelligence.
"Our whole public can see clearly today that hundreds of thousands of citizens could have been spared the horrors of war by acceptance of the Vance-Owen plan two years ago," said Mr Milosevic, "and hundreds of thousands more through acceptance of the international community's plan last year."
No doubt Mr Milosevic has worked out how a strengthened General Mladic will fit into this happy scenario. But he has not let anyone else in on the secret.