The strategy for bombing Bosnian Serbs in the event of an attack on Gorazde was finally agreed by Nato ambassadors in the early hours of yesterday morning.
However, Bosnian Serb aggression was focusing not on Gorazde but in the Bihac enclave of north-west Bosnia. Appearing, once again, to be reacting way behind events, Nato's planners were scrambling to draw up a strategy for Bihac.
Nato ambassadors say the Gorazde air strikes plan produced a major breakthrough in the Western allies ability to respond swiftly to new attacks by Bosnian Serbs, by simplifying the so-called "dual key" command and control structure whereby both Nato and the United Nations must agree to action.
Until yesterday, the UN decision to "turn the key" had to await agreement from civilian leaders, with long delays as decisions were referred first to Yasushi Akashi, the UN special envoy, and then to Boutros Boutros- Ghali, the Secretary-General, in New York.
The 16 Nato allies agreed yesterday that in future the "dual key" should operate at "theatre level", cutting out delays and giving the UN and Nato commanders in the field the joint power to order strikes when Bosnian Serb attacks are imminent. The US has scorned the "dual key'', calling for it to be abolished altogether.
Mr Boutros-Ghali last night relinquished his role to General Bernard Janvier, the French head of the UN Peace Forces, giving the all-clear for a major escalation of Western military involvement in the war.
Mr Akashi also delegated his authority in approval of close air support, or the use of air power to defend UN personnel, to General Janvier, who is authorised to delegate it further to the Unprofor commander in Bosnia, the British Lieutenant-General Rupert Smith, when operational circumstances so require.
Nato ambassadors made clear yesterday that the West has taken an enormous step forward towards presenting a real threat to the Serbs.
There were some indications yesterday that the US might have pushed for Nato to move ahead with its military strike plan even if the the UN Secretary General had refused his consent. Other allies, particularly Britain and France, who had troops on the ground, have been more cautious.
Nato ambassadors in Brussels defended their decision to focus on Gorazde, saying that they were following the mandate of last Friday's London conference. However, they accepted that Bihac presents the more urgent dilemma and military planners were ordered yesterday to begin immediately adapting the plan for implementation at Bihac. There were also suggestions that the air-strikes strategy could be extended to Tuzla and Sarajevo.
The military strategy that has been agreed describes precisely how air strikes would be triggered and against what targets. The details are sketchy but Nato sources said that once the strategy has the go-ahead, military commanders would be "in no doubt" what form of Bosnian Serb threat would trigger the strikes.
The danger of UN troops being taken hostage had been weighed. While recognising the risks, the message to the Bosnian Serbs had to be tough. "Once the decision is taken to start the military action we would not stop it lightly," said Robert Hunter, the US ambassador to Nato.