WASHINGTON - For a brief, happy period on Saturday, it seemed the United Nations Security Council resolution adopted in New York the previous day had stopped Muammar Gaddafi in his tracks.
To general surprise, the Libyan dictator announced an immediate ceasefire, prompting relief and joy among the inhabitants of the besieged rebel city of Benghazi. The commitment by British Prime Minister, David Cameron, United States President Barack Obama and French President Nicolas Sarkozy to use "any necessary means" to halt Gaddafi's onslaught on his citizens had achieved immediate results. That euphoria did not last long.
Eight years after the US and Britain invaded Iraq, the West is involved - this time with the support of the Arab League - in another deadly and unpredictable military confrontation with a dictator in the Middle East.
Yesterday, as British, French and Canadian warplanes sped towards Libyan airspace, Gaddafi's "ceasefire" had proved a fiction.
His troops had penetrated deep into Benghazi, where street battles and an artillery bombardment continued through the day. News reports estimated at least 26 bodies and more than 40 wounded people had been brought to the city's Jala hospital.
Aides insist Cameron had been in favour of international action from the start.
"We simply cannot stand back and let a dictator, whose people have rejected him, kill his people indiscriminately. "
The path to a UN resolution had been slow and uncertain. On Thursday, there was still no consensus about the imposition of even a no-fly zone, after calls for such a move five days earlier by the Arab League.
One issue throughout, insiders admitted, was the role of America. Britain and France, both smarting from criticisms over their stumbling response to the Arab spring, were happy to take the lead on pushing for military action. The French were keen to make up for the blunder of offering riot police to the soon-to-be-overthrown Tunisian regime in the early days of the disturbances.
Cameron, aides admitted, was "very frustrated" by the criticisms he had received for taking arms dealers with him to Kuwait and Egypt shortly after the overthrow of President Hosni Mubarak and the failure to rescue British nationals in the early days of the uprising in Libya.
Distancing the US Administration from proposed military action was also, a Downing St source admitted, part of the process of building support for the UN resolution.
Cameron spoke to Obama shortly after it was passed but that was the first time in eight days. It was important, the source said, that this did not look like a Western initiative - the shadow of Iraq was ever present.
"We have been thoughtful about the Prime Minister's interventions and the first calls on [Thursday] were to Arab countries," said one source. Indeed, while the White House was not troubled by calls from London during the week, Cameron twice rang the Prime Minister of Qatar, Hamad bin Jassim bin Jaber al-Thani.
The problem with the United States, however, was the lingering doubt that the Obama Administration wanted to get involved at all.
The most obvious hurdle was Robert Gates, the Defence Secretary. Gates has an unusual claim to fame in Washington: the only Defence Secretary - and only senior Cabinet member - to have served under both a Republican and Democratic President.
The former CIA director was a voice valued by first George W. Bush and then by Obama. Gates speaks quietly, but with a frankness unusual in Washington. He is due to retire at the end of the year, and this has given him the freedom to be almost as frank in public as he is in private. Over the past few weeks he has been outspoken in opposition to the British and French push for a no-fly zone.
During congressional hearings, he made it clear he thought the no-fly zone would be a mistake, warning that anyone who thought it would be a cost-free exercise was mistaken, and that it would require bombing Libyan air defences. "Let's just call a spade a spade. A no-fly zone begins with an attack on Libya."
He suggested that it would be crazy for a President to embark on another war in the Middle East or central Asia, and at a Nato summit in Brussels last week he succeeded in blocking any move towards a no-fly zone. His concern was that no-fly zones alone could not prevent the massacre of civilian populations, citing Saddam Hussein's slaughter of Shias in southern Iraq after the first Gulf War. He also felt it would prove counter-productive - seen as another US incursion into the Middle East, one that Arabs might view as motivated mainly by oil and that it might stall the Arab spring. Such was the frustration in western Europe that Sarkozy spoke of going it alone. "If nobody wants to do it, France will do it by herself," he told a delegation from the Libyan opposition during a meeting at the Elysee Palace at which he announced France would recognise them.
While Obama and his Secretary of State, Hillary Clinton, were sceptical, even as late as Monday, on whether military action was desirable, they did not rule it out. When Gaddafi then turned events in Libya and appeared to be pushing back the rebels, Clinton changed course and formed an alliance with a handful of aides to influence the President.
With Samantha Power, a senior aide at the National Security Council, and Susan Rice, Obama's Ambassador to the UN, Clinton countered Gates' arguments that Libya was a risk not worth taking.
They were able to show Obama that the Arab world wanted action, and while the President, at times, seemed more concerned with unfolding events in Yemen he was persuaded within 24 hours of the case for action.
By Wednesday, Obama was convinced that the US needed to act and military plans were ordered. The President talked round a reluctant Jacob Zuma, the President of South Africa, and Nigeria was persuaded by others in the Administration.
The West knows that Gaddafi, despite his shambolic image, troupe of female bodyguards and eccentric behaviour, has remained the most powerful force in Libya for more than 40 years for a reason. He survived bombing a Pan Am jet over the Scottish town of Lockerbie, killing 270 people, and there is no doubt - experienced observers of the regime say - of his personal determination to hang on at any cost.