Row over Bosnia threatens rift in Nato unity

NATO is coming under pressure from the United States to mount a show of military strength in Bosnia. The Bosnian Serbs are violating United Nations Security Council resolutions and senior US officials want air power to be used again to stop them. Ambassadors from the alliance yesterday failed to agree on tougher action and the issue is proving divisive. Nato faces the prospect of a wider rift over the next steps in Bosnia, with the US set to lift the arms embargo on the Bosnian Muslims.

The US wants Nato to take a tougher stand over abuses of the weapons exclusion zones in Bosnia, such as that around Sarajevo. American officials say there are 18 uncontrolled artillery pieces around the Bosnian capital. But the UN is reluctant to order attacks to enforce the rules.

US military commanders at Nato's southern headquarters in Naples believe that by allowing the Bosnian Serbs to get away with violations, the credibility of Nato suffers. US officials also believe that by making a stand, Nato will reduce the pressure in Washington to lift the arms embargo on the Bosnian Muslims. Congress has already voted to go ahead with this move, but senior officials believe it could still be halted.

Britain broadly supports a tougher stance. But France and other countries with troops on the ground in Bosnia fear air attacks will endanger peace-keepers in Bosnia. The issue threatens to revive tensions present throughout the Balkan conflict between Washington and the European powers.

The alliance did decide yesterday to extend air operations to cover attacks on UN peace-keepers from Serb-held territory in Croatia. But it will not mount operations immediately, as it needs to put in place tactical air-controllers who can control aircraft from the ground. Arrangements will have to be made with Croatia, as the use of close air support would involve entering Croatia's airspace.

But Nato merely reiterated earlier decisions on the exclusion zones, holding back from harsher threats. 'We have to continue working with the UN to make sure we are on the same wavelength,' an alliance source said.

The UN has repeatedly resisted tougher action over the exclusion zones. Nato and the UN differ over the use of force to back up Security Council resolutions, frustrating US military commanders and Nato officials. But Nato is wary of acting without UN support, and UN authorities are closely involved in the decision-making.

Behind the divisions over air-power are serious conflicts in Nato over Washington's proposal to lift the arms embargo. Britain and France have suggested they will not veto a proposal to lift the embargo, as the US has indicated it would take unilateral action. They will probably withdraw troops if the US goes ahead. But a withdrawal, possibly in hostile conditions, might require the support of Nato and the Americans.