Libya: now what?
Same date, different prime ministers, different Arab dictators.
18 March 2003, T Blair: "This is not the time to falter. This is the time for this house ... to show that we will stand up for what we know to be right, to show that we will confront the tyrannies and dictatorships and terrorists who put our way of life at risk, to show at the moment of decision that we have the courage to do the right thing."
18 March 2011, D Cameron: "We should not intervene in other countries save in quite exceptional circumstances ... (but) we cannot have a failed pariah state festering on Europe's southern borders."
So have we embarked on another war without end? More than nine years after British forces joined the US-led intervention in Afghanistan, and eight years to the day since Tony Blair delivered his passionate defence in the House of Commons of his decision to commit UK forces in Iraq, are we once again going into battle with too many questions unanswered?
It has become a cliché to observe that all wars are easier to start than to end. UN security council resolution 1973, approved last night by 10 votes in favour with five abstentions (Russia, China, Germany, Brazil and India) states the objective of the Libya intervention clearly enough: to protect civilians and civilian-populated areas under threat of attack.
It authorises member states to use "all necessary measures" with the exception of a foreign occupation force - which is universally understood to mean Yes to air attacks, but No to troops on the ground.
Over the coming hours, we - and especially the people of Libya - will wait anxiously to see what happens next. Maybe some of those around Muammar Gaddafi will turn against him - but the key remaining figures in his regime are members of his own family, so it seems unlikely.
Maybe his forces will halt their advance towards Benghazi, at least for the time being. A siege is just as much an option as an assault.
Maybe US, British and French warplanes will start bombing his tanks and artillery pieces along the coast road. Maybe by mistake they'll hit civilians as well as military targets.
But I was struck listening to David Cameron's statement in the House of Commons this morning (apart from the fact that, this being a Friday, the place was virtually deserted) by how careful he was to spell out that this is a very different kind of operation, under a very different kind of prime minister, from the one we embarked upon eight years ago.
He emphasised the degree of regional support for military intervention - both the Arab League and the Gulf Cooperation Council have backed the idea of a no-fly zone. Not like 2003.
And he spoke of the "clear legal basis" for the action - an unambiguous Security Council resolution, with clear advice for the British cabinet from the attorney-general, which he said had been "read and discussed" by ministers this morning. He didn't need to spell out to MPs the differences from eight years ago.
So how will this end? No one knows. How long will it take? Same answer. If Gaddafi is defeated, overthrown, or killed, what or who will take his place? Answer as above.
Last Friday, during the discussion on the Arab uprisings that we recorded at Chatham House, I asked Sir Jeremy Greenstock, who had been the UK ambassador at the United Nations in the period leading up to the Iraq invasion: "As you watch events unfolding, do you say to yourself: 'Here we go again'?"
We didn't know then that within a week a strongly-worded Security Council resolution would have been approved - but Sir Jeremy replied without a moment's hesitation in the affirmative.