General Mladic was told that "the attacks against the 'safe areas' cannot be tolerated". He was informed that the three countries would resort to any means necessary to reinforce or resupply United Nations troops in these areas. There was a specific warning that "if military action is undertaken against Gorazde, substantial air actions will be mounted. If necessary, these actions will be at unprecedented levels".
Air Chief Marshal Sir William Wratten, Commander in Chief of RAF Strike Command, delivered the message in person to General Mladic at a government rest house in Belgrade on Sunday. The Air Chief Marshal, who was air commander and architect of British bombing strategy during the Gulf war, was joined by high-ranking American and French officers. All three men presented a jointly agreed text, which was conveyed also to the Serbian President, Slobodan Milosevic.
In addition to the collective ultimatum, Air Chief Marshall Wratten gave a warning on behalf of the United Kingdom. He said any further hostage- taking by the Serbs would be seen as an attack on vital national interests and would attract severe reprisals. The Bosnian Serb leadership would be held "individually responsible" if any harm came to British soldiers, he said.
The Bosnian Serbs yesterday threatened dire consequences if Nato air strikes were launched. But General Mladic is said to have repeated to the three officers his demand that the Bosnian Muslim forces cease using the "safe areas" as springboards for military action. He said he wanted the areas demilitarised.
The language of the ultimatum suggested the three powers regard all the "safe areas", with the possible exception of Bihac, as subject to the warnings against assault. But only Gorazde was singled out for a guarantee of massive air strikes in the event of attack. "That is because there was a general feeling at last Friday's London conference that the fall of Gorazde would mean the end of the UN mission," a British official said.
Yesterday the US Defense Secretary, William Perry, refused to rule out heavy Nato air strikes in response to continuing attacks on Sarajevo and Bihac. "It does not rule that out. Indeed, quite the contrary," he said, when asked if the allied ultimatum was confined to attacks on Gorazde.
Despite the tough talk, the alliance remains divided over the practical details. Nato military planners meeting in Brussels failed to agree a concrete strategy for air strikes, but officials believed that a mandate for military commanders should be ready by today. Disputes between the powers over how and when air strikes should be carried out have hampered efforts to produce a battle plan, promised for yesterday. Last night the military chiefs were consulting their political leaders.
"We now have a very detailed military document on the table that is close to completion," a Nato official said. The final document is expected to focus on Gorazde, but will also make proposals for raids on the Muslim enclaves of Bihac and Zepa, both of which have come under heavy Serb attack.
Debate has been heated over who should decide when air strikes are launched. The US opposes continuing use of the "dual key" arrangement, whereby decisions are taken jointly by the UN and Nato. The UN Secretary General, Boutros Boutros-Ghali insisted yesterday that it remained his decision to launch air strikes. Today's plan is expected to clarify command structures.