JIM LEHRER, one-half of the highly-regarded MacNeil- Lehrer News Hour, was seeking elucidation from the Secretary of State, Warren Christopher, on the latest divisions over the administration's Bosnia policy. Who, he asked, 'really calls the shots on foreign policy?'

Mr Christopher's answer was immediate. 'The President calls the shots.' And therein lies the rub.

Once again, Washington is seeking to repair a muddle over its Balkans strategy, with the Pentagon last weekend seemingly ruling out the use of force to relieve the besieged Bosnian town of Gorazde - only to be courteously but firmly contradicted, first by the National Security Adviser, Anthony Lake, and then by Mr Christopher in his television interview on Thursday evening.

According to the Secretary of State, the urgent priority is to get UN peace-keepers to Gorazde, confronting the Bosnian Serbs with the threat of air strikes if they interfere with the peace-keepers' mission. Of Defense Secretary William Perry's declaration that the US 'would not enter the war' - which some State Department officials privately derided as an 'open invitation' for Serb aggression - Mr Christopher merely remarked that it was 'perhaps accurate at the time'.

Publicly, the Pentagon has fallen into line. Quickly, Mr Perry's spokeswoman asserted that 'no daylight' existed between the two departments. Both, she insisted, agreed that 'all options should be looked at all times' in Bosnia. But once more, President Clinton's discomfort with foreign policy has been obliquely underlined.

While his top officials have politely bickered, the Commander-in-Chief has spent the last fortnight out of Washington promoting his health- care policy, virtually silent on the crisis at Gorazde. And one measure of both the President's and Mr Christopher's perceived lack of authority is the rapid emergence of Mr Perry as a foreign-policy force in his own right.

In his job for barely two months, the mild-mannered Defense Secretary is a management and procurement specialist, not celebrated for strategic thinking. Yet of late he has been the most forceful propounder of US policy, mixing avowed caution on Bosnia with trenchant realism about Russia and an increasingly hawkish stance on North Korea. The Washington Post this week called him the 'unexpected heavyweight of the beleaguered Clinton foreign-policy team'.

Interviewed by Jim Lehrer on Thursday night, Mr Christopher was again forced on to the defensive, insisting there were 'absolutely no' turf fights with his old friend Mr Perry and that foreign policy was ultimately determined by Mr Clinton.

The US will only send in ground troops after a comprehensive peace agreement between the three warring parties in Bosnia. In a speech this week, Dr Lake repeated that if a settlement was achieved, any US contingent - which the adminstration expects to be less than half the total UN force - would be properly equipped to do the job. It would 'go in strong', as Dr Lake put it.

The situation in Bosnia had reached a 'pivotal moment', he said. Progress was fragile. Addressing himself to Muslims as well as Serbs, Dr Lake warned all parties against seeking to improve their bargaining position by renewed fighting. The pursuit of marginal advantage could 'plunge all of Bosnia back into bloodshed'.