FOR AN AMERICAN ambassador facing an international crisis, the political swamp of Washington can suddenly appear as foreign as his host nation's capital. If events go badly wrong, he can find himself shut out from his masters' key policy decisions, but scapegoated by hungry cliques of foreign-affairs analysts, insiders and administrators. Even in less volatile times there is the threat of the sneer that he represented his hosts' interests in Washington rather than America's abroad. Recent history has thrown up some stark images. As North Vietnamese troops closed on Saigon in 1975, there was the controversial Ambassador Graham Martin, addled by pneumonia and a chronic lack of sleep, clinging to the belief that his ally's southern flanks could be defended. Martin refused to order the evacuation, raging obscenely against his internal critics at 'Foggy Bottom' - State Department headquarters. He was finally overruled from Washington and eventually put into a helicopter from the embassy roof just hours before the final fall. More recently came the image of Ambassador James Sasser staring from a shattered window of the US Embassy in Beijing in March 1999. The US-led Nato bombing of China's Embassy in Belgrade sparked violent anti-American protests across the mainland, just as Mr Sasser's term was ending. Beijing put relations on ice, bringing then-president Bill Clinton's engagement policies under more fire within the Republican Party's right wing and making Mr Sasser a target yet again. Now it is Mr Sasser's replacement, Admiral Joseph Prueher, who is in the hot seat. The lean, fit frame of Admiral Prueher has been a familiar sight on television screens over the past 11 days as he has scuttled up the steps of the Chinese Foreign Ministry in Beijing for more negotiations over the Hainan Island spy-plane impasse. The talks, over the 24 American aircrew and the EP-3E spy plane stranded on the mainland following its collision with a Chinese jet fighter, may not have reached Belgrade - much less Saigon - proportions, but with each passing day, Sino-US relations were put in greater danger, analysts and US officials warned. Admiral Prueher, whose position as ambassador was confirmed in November 1999, was the first to deliver some of the Bush administration's toughest statements when he described the detention of the crew as being 'inexplicable and unacceptable and of grave concern'. He was also one of the first to express careful remorse when he stated: 'It appears also that the Chinese have lost an aircraft and we are sorry that has occurred.' Yesterday, he delivered a letter to Chinese Foreign Minister Tang Jiaxuan that included expressions of regret over the loss of the Chinese pilot and his plane and for the spy plane having landed on Hainan without verbal permission. This signalled the end of the impasse, with first the Chinese side announcing the aircrew would be released after 'necessary procedures' and then Mr Bush saying they would be released 'promptly'. As the pressures mounted, Admiral Prueher appears to have had the ear of his new masters and was in direct telephone contact with the Oval Office. The four-star admiral is understood to have recently told former military friends that his latest job is more challenging than anything he faced during his glittering 35-year naval career. It was a life that saw him fly more than 50 combat missions over Vietnam, become captain of an aircraft-carrier battle group and, most recently, command the US forces in the Pacific. If his sentiments about his current job are true, nothing in his career would top the challenges he now faces. Even after the crew's release, he will be engaged in continuing negotiations over the spy-plane incident. Like Mr Sasser, Admiral Prueher's toughest role came just as he is expected to be preparing to leave. Like all Clinton-era appointees, Admiral Prueher resigned as a matter of formality with the inauguration of new Republican President George W. Bush. He is tipped to be replaced shortly by Hong Kong-based lawyer Clark 'Sandy' Randt, an old college friend of Mr Bush. Like Mr Sasser, Admiral Prueher, 58, is no stranger to controversy. He lobbied for the job at a time when the Clinton team was struggling to find someone who wanted it - and would be acceptable to the fierce anti-China lobby in the Republican-held Congress. He was, after all, taking power at a time when congressional claims of Chinese espionage were reaching a height and concern was mounting over military buildups in the Taiwan Strait - all ahead of a bruising presidential-election season in the US. During his confirmation hearings, Admiral Prueher positively charmed the pugnacious veteran chairman of the Senate Foreign Relations Committee, Jesse Helms, one of the most outspoken of Congress' China bashers. Admiral Prueher weaved a heavily nuanced line of engagement, insisting America must deal with China from a position of political, economic and military strength while staying aware of the 'immense challenges' the leadership faced. 'Our approach needs to be one of respect, and also strength, in dealing with and working and moving forward with the Chinese,' Admiral Prueher said. Nodding sagely, Mr Helms - who still refers to 'Red China' - surprised many by lapping it up. He may think nothing of holding up nominations for months, but Mr Helms paid Admiral Prueher the courtesy of calling him 'Mr Ambassador' even before he was confirmed. Others, suspicious of military engagement with a burgeoning PLA, have been considerably less generous. Admiral Prueher is well known among Washington's extensive pro-Taipei lobby for his call as Pacific Commander to dispatch two aircraft carriers into the Taiwan Strait as China tested missiles ahead of the island's elections in 1996. But his drives to foster a still-fledgling military-to-military engagement afterwards remain controversial. 'I didn't have anybody in China to talk to, and we had no military relationship,' he said later. 'We need to have an ability to have that communication so we don't make any miscalculations and can advise our civilian bosses beforehand.' His efforts since 1996 have made him one of the most high-profile US officials inside China, with some even suggesting he is better known in Beijing than at home. Larry Wortzel, a former US defence attache in China who is now with the conservative Washington think-tank the Heritage Foundation, is one national security analyst who warns that, after the spy-plane incident, the ambassador could pay for his early efforts to get closer to the Chinese military. 'He has been too pro-engagement, and this sort of event should be a wake-up call to remind us whom we are dealing with,' Mr Wortzel said. 'If they know they have an apologist, they think they will get an apology . . . Frankly, from the time he was [Pacific Commander], I think he has been too accommodating to [China's] feelings and sensitivities.' Mr Wortzel added, however, that Admiral Prueher was probably the best person to handle the spy-plane crisis, given his extensive knowledge of America's surveillance needs off China's coasts and the laws guiding such work. Admiral Prueher has also ruffled feathers with the business lobby, a pro-engagement group that often finds itself at odds with the more hawkish national-security types. Some warn that he has concentrated too much on human rights and security issues, leaving the hard work of trade-reform issues and economic openness to other embassy staff. 'When leading American chief executives turn up in Beijing and struggle to get an appointment with the ambassador, it annoys people,' one veteran lobbyist said. 'Surprisingly, the wider business story is just something Admiral Prueher has not been so interested in.' Other Washington insiders coldly warn that Admiral Prueher's expected departure provides the administration with an exploitable opportunity to help forge a solution. As he is leaving, it would be no harm for him to present a further message of condolence - but not an apology - at any Beijing ceremony for the dead Chinese pilot in a bid to curb wider mainland demands. 'He would be the perfect sacrificial lamb,' one analyst said. Mr Randt's appointment to replace him has yet to be announced, but his name is understood to sit on top of Mr Bush's list following the completion of lengthy background checks. Speculation is mounting, however, that the crisis could force a different character forward should it seriously dent ties. Mr Randt certainly appears a progressive choice, reflecting years of broad engagement ahead despite the Bush team's 'strategic competitor' rhetoric. A fluent Putonghua speaker, he is a respected veteran of the China-trade legal scene and has helped several large mainland concerns raise funds in the US. More importantly, his years with Mr Bush at Yale University in the 1960s will put him just a phone call away from the Oval Office. Such access is highly valued in Washington - and in Beijing. But Mr Randt will no doubt want to be aware of other considerations should he find himself representing Washington in Beijing - particularly the old capital standard: 'If you want a friend in Washington, buy yourself a dog.' Greg Torode is the Post's Washington correspondent