He was speaking after British United Nations forces shot dead two Croatian gunmen who attacked a Muslim convoy near the British base at Vitez - the first time British troops killed anyone since being deployed to Bosnia last year. There were no British casualties.
Fears are growing that the Croats will seek revenge for the deaths. Croatian civilians in the area were quoted last night as saying that 'Unprofor (UN Protection Force) in central Bosnia have become madmen.'
As Mr Major spoke of contingency plans to meet 'widespread deterioration on the ground', British UN officials warned they could not operate in conditions of anarchy. 'We have been using our vehicles to project power but when we have to fire on people, then, yes, we are getting to the stage of anarchy here,' one officer said.
The Defence Secretary, Malcolm Rifkind, said last night on television that Britain would consider withdrawing its troops if they were not able to carry out their peace-keeping task 'relatively safely'.
Mr Major was quick to establish that the British troops had acted within their mandate. 'Let me make it absolutely clear our commander on the spot has complete authority to take any decision he considers necessary to protect the safety of our troops,' he told the Welsh Tory party conference at Llangollen.
But in response to opposition calls for a withdrawal of the British contingent, he said: 'There are two criteria governing their presence there: Can they carry out their mandate and can they carry out their mandate without unacceptable risk?'
British Warrior armoured vehicles returned fire with their 30mm cannon when the head of the 'Convoy of Joy' was repeatedly shot at by Croatian soldiers. The British had fired warning shots. The stalled 200-vehicle convoy later came under a barrage of Croatian mortar fire in revenge for a Muslim army offensive in central Bosnia that has killed and displaced thousands of Croats.
Major James Miles, a spokesman for British forces in Vitez, said: 'The UN cannot operate properly where anarchy reigns.' As shells were seen exploding in the area, UN peace-keepers said they believed Muslim artillery was blasting Croatian targets.
Major Miles said Croatian leaders had promised safe passage for the convoy, bringing supplies to the besieged town of Tuzla, but Bosnian Croats were taking their revenge. 'After they have been chased from their villages, murdered, plundered, they have obviously got something together and they are turning now to fight back against their neighbours,' he said.
The convoy was first attacked and plundered and eight of its drivers shot on Thursday night in Novi Travnik, west of Vitez. Some 30 others were captured by Croatian troops. UN sources said the Croats killed two drivers yesterday. One, shot at close range, was left slumped in a blood-stained cab.
Last night a UN spokesman in Kiseljak implied that the British force had abandoned its attempt to protect the lorries. He said the convoy had been broken up and was now 'scattered all over hell's half acre'.
Belgrade was quick to capitalise on the fact that it was now Croats and Muslims rather than Serbs who appeared to be the villains. A press release from the Yugoslav embassy in London said that 'if Croat or Muslim forces attack British Unprofor troops in Bosnia, then Bosnian Serb units will immediately come to the aid of the British troops because of the traditional ties and an old alliance relationship'.
It quoted sources close to the High Command of the Yugoslav army as saying Bosnian Serb forces 'are prepared to offer, should need be, all necessary assistance to the British Unprofor contingent in Bosnia-Herzegovina', adding: 'Bosnian Serb forces have never mounted an attack against the British troops'.
The Bosnian Croat leader, Mate Boban, citing 'brutal Muslim aggression', said that he would not meet President Alija Izetbegovic of Bosnia in Geneva this weekend.
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