At dawn on a small wooden bridge in New Mexico, Klaus Fuchs once passed the blueprint for the H-bomb to Harry Gold, his handler from President Vladimir Putin's old employer, the KGB.
And it was on a small wooden bridge in Virginia that Robert Hanssen, Russia's recently arrested spy within the FBI, would meet his man from Moscow's secret services.
But this weekend the bridges between Washington and Moscow - and with Beijing too - are collapsing as George W. Bush rattles the sabres of a new Cold War across Europe and the Pacific.
In an echo from another time, four senior Russian envoys will leave Washington during the coming days, with a further 46 to follow before the muggy summer descends on the Potomac. And in strict accordance with the rules of Cold War, Russia's retort is swift and symmetrical: four senior Americans to leave imminently, with 46 to follow after the ice thaws on the Moskva.
And no sooner had the order for them to leave been handed to Russian Ambassador Yuri Ashakov than US Defence Secretary Donald Rumsfeld took another bellicose stride across the Pacific, towards a new arms race with China - giving Bush a 90-minute lecture on his plans to overhaul America's arsenal to face the new Chinese threat.
Based on the premise that the United States' Far Eastern flank is the most likely theatre for military operations, Rumsfeld said that he wants to replace dependence on aircraft carriers and short-range fighters with long-range bombers capable of flying across the world's widest sea to fight and win a nuclear war.
The Rumsfeld briefing coincides with a White House pledge that the US will push ahead with arms sales to Taiwan. The Chinese have thus far responded with cryptic remarks about continued friendship, but the formality was shattered in an interview with President Jiang Zemin in the Washington Post urging the US to halt the sale, which would cause his own country to accelerate its military modernisation programme. 'The more weapons you sell,' he said, 'the more we will prepare ourselves in terms of national defence.'
The tit-for-tat with Russia and belligerent glare towards China are partial responses to a question that America thought might be answered at the end of the Bush administration's first 100 days, but to which the first 60 have already articulately replied: 'Will the real George Bush please stand up?'
For all the talk about a 'gridlock' that might follow his contested election victory, Bush has embarked on a brazen agenda of conservative policies at home and combative international gestures. On the domestic front, he has ridden roughshod over his opponents on tax cuts, the environment and - late on Friday night - organised labour, with a new Executive Order overriding eight years of work safety legislation compiled by the Clinton administration.
Overseas, Bush has ig-nored European allies, bombed Iraq and spurned the North Koreans and Palestinians. But the most serious of these struts onto the international stage, about which he reportedly knew nothing until the final days of his campaign, are the gauntlets hurled last week into the faces of Russia and China.
Mutual expulsions are a carefully choreographed routine. A diplomatic persona non grata is rarely, if ever, punished - they are 'caught' and sent packing while governments go after their own kind. But these are the largest such actions taken since the espionage 'bloodbath' of 1986 and the most aggressive since the collapse of the Soviet Union.
US counter-intelligence claims that post-Soviet Russia has mobilised a determined build-up of espionage in the US out of proportion to American intelligence activity. 'They've flooded the zone,' said David Major, a former FBI counter-intelligence official as part of a PR blitz, 'and as long as they continue flooding the zone it puts a strain on American counter-intelligence.' Other officials say that Putin has strengthened his military intelligence web in the USA.
But there is manipulation in these alerts. During Cold War days, a communication line ran between the KGB and CIA, 'the Gavrilov Channel', to maintain checks and balances on numbers operating on each side.
Last week the Washington station chief of the post-communist SVR service was reportedly left intact - a signal that Bush accepts the Gavrilov principle and that the US and Russia need each other's intelligence services in modern combat against drugs, fraud and organised crime.
Although CIA director George Tenet supported the expulsions, the agency itself was opposed, said one source, knowing that they would provoke retaliation and reduce CIA numbers in Russia.
To real experts, the core issue is not the Boy's Own melodrama of espionage but the far more perilous monitoring of Russia's isolated but vast nuclear arsenal and American commitment to the bilateral co-operation programme that destroys warheads and stops proliferation. A recent element in the degeneration of Russo-American relations was Rumsfeld's view of Russia as a 'nation of proliferators', and his deputy Paul Wolfowitz's that 'these people will do anything for money' - sneers which run contrary to most experts agreeing that miraculously few 'loose nukes' have found illegal passage out of Russia.
Among the leading observers of Russia is Susan Eisenhower, director of the Eisenhower Foundation and granddaughter of Ike - general, President and founder of Nato. Interviewed by The Observer on Friday, Eisenhower questioned the validity of the Hanssen panic and warned: 'The irony is that the US is in a more vulnerable position than the Russians.
'We have hundreds of professional personnel all over the most remote and sensitive nuclear sites in Russia under the co-operation treaties. The big issue is access to sensitive sites, and this is contingent on the good grace of the Russian government.
'But now,' she continued, 'the Russians have the absolute right to say at any time "for security reasons we can't continue to allow you access to our most sensitive sites".' Eisenhower added: 'There are a number of ways to handle this situation, and one has to wonder why the administration decided to do so this way. What else did they expect the Russians to do? It probably means that the administration is not as sympathetic to the monitoring co-operation programme as was the case in the past, and that is very serious indeed.
'The Russians are very prideful of the fact that there has been so little proliferation, and it is dangerous for the US to undermine that.'
Bush is seen as using the Hanssen case as a pretext to reduce Russia's intelligence presence in America, but experts regard the rationale as political.
The expulsions are the latest in a rapid series of antagonisms, including the missile defence screen, threats to cease aid and a meeting last week with Chechen 'ambassador' to Washington Ilyas Akhmatov which - whatever the merits of the case - would be equivalent through British eyes to meeting the IRA. Putin has thrown his own challenges: arms trading with Iran, repression in Chechnya and tacit backing for the tyrannies in Belarus and Ukraine.
The engine behind Bush's foreign policy, National Security Adviser Condoleeza Rice, has been spoiling for a fight with Moscow for years - long before she bewitched Bush with her ability to talk baseball and had a view of Russia that applied whether the country was communist or not.
Rice is a lifelong hawk who switched from the Democrats to Republicans because of Jimmy Carter's 'feeble' response to the invasion of Afghanistan, has long insisted that Russia 'modify' the bedrock ABM treaty of 1972 and accused Bill Clinton of 'romanticism' in his relations. She opposed détente and aid programmes by the World Bank and IMF, and her finest hour came when these were discredited by corruption scandals.
But Rice's last experience in office was during the final years of the communist regime and, says one former Russian desk official in the Clinton State Department: 'Condie is not a Russian expert, she's a good Soviet-ologist, which is not the same thing.'
Russia is not the only country facing Bush's new hard line. Briefing The Observer two weeks ago, Bush's spokesman Ari Fleischer made it clear that European objections to the missile defence screen would make no difference to the ultimate US objectives; negotiations with North Korea have been frozen. And last week the US dealt a triple blow to the world's fastest-emerging power, China.
As Rumsfeld submitted his defence proposals, Bush made it clear that he will push ahead with selling the Aegis missile radar system to Taiwan - enabling the island to steal a military edge over the mainland - which China stresses will rupture relations between Beijing and Washington. This he did while shaking hands with Chinese Deputy Premier Qian Qichen, who warned against the Taiwan sale and was told by his host that the warmth of the Clinton era would be replaced by a policy that was 'respectful' but 'firm'.
Rumsfeld also briefed senior Pentagon officers when their chief of staff, General Henry Shelton, was away - reflecting the domination of military affairs by White House political thinking and exclusion of senior military from policy-making. Rumsfeld told them that operating across the Pacific will require an additional emphasis on 'long-range power projection' - which means dispatching bombers and firepower across thousands of miles.
Strategically, the shift requires building a new generation of long-range bombers which may or may not be an unmanned enhancement of the B-52 warhorse that the US has been making since 1954 and is commissioned until 2020.
Politically, it means infuriating and alarming the Chinese. The Beijing government's greeting to Washington upon Bush's inauguration stressed that 'we don't like your national missile defence, but we are willing to talk about it. We believe our differences must be subordinate to our common interests - but with one exception. If you take the crucial step towards extending missile defence to Taiwan - that is a step too far'.
Although Rumsfeld's proposals do not specifically extend the screen to cover Taiwan, it does swing America's military posture from the European theatre arraigned against Russia to a more aggressive readiness to fight a war across the Pacific, as Russia apparently weakens and China is perceived to be strengthening its nuclear arsenal. Between the two, the United States is closer to battle stations and more isolated than any time since Bush's father, George H, hailed the dawn of the 'New World Order' a decade ago.
• Additional reporting by Amelia Gentleman in Moscow and by John Gittings in Shanghai
Related articles
World Dispatch: Russia reacts angrily to 'spy' expulsions
22.03.2001: Timeline of 'spy' expulsions
04.03.2001: Alarm as Dublin trains 'KGB'
26.02.2001: Russian faces spy trial over UK trip
23.02.2001: Spy claim forces lie-test rethink
25.02.2001:The spy who loved being out in the Cold
Useful links
Russian embassy in Washington DC
US embassy in Moscow
FBI
FBI press release on Robert Hanssen's arrest
Special operations.com
The 1948 Alger Hiss spy case
The 1951 Rosenberg spy case