For the US, the episode highlighted the dilemma of the post- Lockerbie era - that warning travellers of a danger has the potential to expose sources and anger the country concerned.
For Jordan, the controversy has thrown unwelcome light on threats to its stability from factions based beyond its borders - and highlighted King Hussein's determination to present the country as one which has contained Islamic extremism.
The US warning came on 1 March, when the State Department announced a 'specific and credible' threat to Americans in Jordan, particularly those travelling by tour bus. The warning was said to be based on intelligence that a militant Islamic group based outside Jordan planned to attack an American bus in Petra. A growing number of Christian pilgrims travel by bus to Jerusalem, and the warning inevitably raised the spectre of Egyptian-style anti-Western, anti-Christian militancy.
The US produced no evidence. But as one Western diplomat put it: 'No one in the State Department is nowadays going to risk his neck by sitting on information like that'.
Jordan, which prides itself on impeccable security, insisted that there was no such threat, that no Western tourists had been attacked in recent years and that Jordan was now safer for Americans than America. 'They were furious from the King on down,' said one commentator.
With tourism just picking up after the Gulf war, the potential impact of the warning was enormous. Its apparent arbitrariness provoked suspicion in Amman about US motives.
Was the warning designed to pressure Jordan to toe the line over the peace process, or was it a convenient way to fan the flames of hatred against Islamic fundamentalists? The arrest of Mohammed Salameh, a Palestinian with Jordanian citizenship, in connection with the New York Trade Centre bombing, heightened Jordan's sensitivity to such theories.
Two weeks after the US warning, Jordanian officials, on the King's specific instructions, leaked their version of events. They said that one month before the US warning, Jordanian police on the Syrian border arrested two armed militants in a Lebanese- licensed car, who confessed to planning an attack on a tourist bus in Petra. They were associated with the Hizbollah Palestine faction, based in Syria and believed to be connected to Islamic Jihad, which operates in the Israeli occupied territories.
The Jordanian officials said this information had been given to the US embassy in Amman, and that the US State Department blundered by issuing a warning after the threat had been neutralised, thereby compromising sources.
However, the Jordanian leak did confirm that terrorists are attempting to infiltrate Jordan from Syria. This in turn confirms predictions that extremists will have an interest in stirring ferment in Jordan if the peace process continues. So far the violence in the occupied territories has not spread to Jordan. The Islamic groups are incorporated in the political process. A successful attack on an American target in Jordan would cause acute embarrassment to the regime.
If Jordan catches infiltrators in future, some observers believe it may put its own interests first and withhold the information from the US.