US demands end to Russian spying: As Yeltsin calls for a summit to settle former Yugoslavia, Patrick Cockburn in Washington and Andrew Higgins in Moscow report on a growing chill between old Cold War enemies

ONLY A MONTH after meeting in Moscow, Presidents Bill Clinton and Boris Yeltsin yesterday jettisoned bonhomie to behave more like their cantankerous Cold War predecessors, co-operation eclipsed by a row over espionage and anxieties over spheres of influence.

Russia and the United States are still a long way from the deep freeze of Ronald Reagan's early years in the White House but a definite chill has set in as Russia sloughs off a largely passive, pro-Western role to reclaim superpower prerogatives.

In a sign of a more assertive, confident diplomacy, Mr Yeltsin yesterday proposed a one-day summit with the US, Britain, France and Germany to work out a settlement in former Yugoslavia. But the US, undecided whether the Balkans are a zone of co-operation or renewed confrontation, reacted coolly. The White House press secretary, Dee Dee Myers, said a summit would need 'a lot of preparation'. Britain called the idea 'interesting'.

The US is insisting Russia halt all espionage against it in the wake of the arrest as a spy of Aldrich Ames, a senior member of the CIA. The Secretary of State, Warren Christopher, said: 'The continuation of Russian espionage activities against the United States is unacceptable.'

The US is demanding that Russia withdraw the diplomats from its Washington embassy who controlled the spying activities of Mr Ames and his wife, and is also reportedly asking the Russians to take the unprecedented step of telling Washington what they learned from him.

The Clinton administration is trying to react strongly to what may be the worst case of espionage in US history without damaging long-term relations with Russia and Mr Yeltsin. Mr Clinton has asked for Mr Yeltsin to handle the affair personally.

Ivan Gromakov, the Russian intelligence chief in Washington who probably dealt with Mr Ames, recently returned to Moscow at the end of his tour of duty. Voluntary withdrawal of other Russian intelligence officers would let the US avoid expelling them and perhaps provoking Moscow to respond with expulsions of American diplomats.

Speaking before the Senate Foreign Relations Committee, Mr Christopher said: 'The effect of this incident on our relationship with Russia will depend upon Russian actions in the days ahead.' Withdrawal of some diplomats would be easy for Moscow to concede, but revealing information already passed to Moscow by Mr Ames would make it difficult to recruit agents anywhere in the world.

Senator Dennis DeConcini, chairman of the Senate Intelligence Committee, suggested the US should freeze aid to Russia for 60 days while the full damage caused by 'America's Philby' - thought possibly to include deaths - is assessed. Moscow's spy-masters, though, voiced bewilderment that Washington was so upset. President Clinton did not rule out a freeze but said it was still too early. 'I think we should wait and see what the full response of the Russians is before we make any other determination,' President Clinton told a press conference.

During Mr Clinton's visit to Moscow he and Mr Yeltsin promised not to aim nuclear missiles at each other and spoke of 'putting the last full stop on the last Cold War problem'.

How much has changed was highlighted by a particularly aggressive attack on the West's policy in Bosnia by Mr Yeltsin's chief spokesman, Vyacheslav Kostikov: 'There is an impression that Nato, despite its rhetoric, is still a prisoner of the ideology of the Cold War. This does not take account of the changing political realities caused by the birth of a democratic Russia.' Mr Kostikov, notorious for his shrill tone, used to direct his venom at Mr Yeltsin's Communist enemies in parliament but, like much of Russia's political elite, he now often prefers targets abroad.