Today, Britain has a new foreign policy - and it isn't neo-conservatism. It's the politics of "it depends".

by Paul Goodman

At the last election, Conservative foreign policy was neo-isolationist.  It wanted the repatriation of some powers from the EU and a "solid, not slavish" relationship with America - code for no more liberal wars and lots more trade missions.  True, the party was committed to intervening by maintaining aid spending in real terms, but this was a reminder that Tory foreign policy would stress butter rather than guns.

Today - in the wake of the British-and-French led UN resolution on Libya - it will be claimed that there's now a new Conservative foreign policy - that we're back to Tony Blair, the Iraq War and liberal internationalism, as set out in Blair's Chicago speech.

This is wrong.

It's true that the Prime Minister has discovered, when confronted with an international crisis, that he's interventionist instincts of which he seems previously to have been unaware.  Perhaps this is the ghost of Winston Churchill at work - the legacy of standing up to dictators which triumphed at last in the 1940s, went tragically awry at Suez, pulsed during the Falklands war, and Blair drew on over Iraq.  This instinct can work cross-party.  Foot backed Thatcher over in 1981, Duncan-Smith supported Blair in 2003, and it's notable in the last few days that Miliband backed David Cameron and Sarkozy over the need for a UN resolution.

None the less, the Libyan decision doesn't mean that we're now back-to-the-future, with a neo-conservative foreign policy rampant in Downing Street.

Do we have a national interest in stopping Gaddafi?  Yes, because we don't want a refugee problem across the sea from southern Europe, and Opportunity Knocks for Islamists in the middle east.  The Prime Minister calculated, correctly, that if Libya's dictator was allowed to triumph, a message would have been sent out to the region's rulers.  If in doubt, be a Gaddafi, not a Mubarak.  Slaughter your opponents and the west will do nothing.  Its talk of demoracy is empty.  So if you want help, don't turn to Washington or London: go to Tehran instead.

Do we have enough of a national interest in Libya, then, to commit our troops alone - and make a big military commitment at the time of a defence spending scaleback?  No, clearly not.  But that's the point about national interest.  It isn't like sovereignty - something you either have or haven't.  It has different levels and gradations.  To use a risky figure of speech, the national interest isn't like virginity.  It's more like sexual relations as a whole: something that has different degrees of engagement.

So back to the questions.  If we don't have enough national interest to commit our troops alone, do we have enough to act in concert with the United States, still the greatest military power on earth, and with others?  Yes.  Was Cameron therefore right to push for a UN resolution?  Yes.  Should he have seized on the Arab League's backing of a no fly zone as diplomatically decisive, and used it to build pressure on a vaccilating Obama?  Yes.  (Tim's right to dismiss attempts to spin his wobbling as leadership, and it's notable that in the Commons today Cameron confirmed that he didn't speak to Obama for a week.)

Does this mean that Britain should now cobble together international military intervention in Guinea or Zimbabwe or the Sudan - and perhaps send in some of our own troops?  No, because the balance of our national interest is against it.  Will the Libyan scheme work without "boots on the ground" and with an arms embargo on both sides - in other words, effectively on the rebels?  Maybe not - but if it doesn't, and a stalemate ensues, Britain's not committed to sending in ground troops, though we should certainly push to get the arms embargo lifted.  (Bob Stewart asked a sharp question about this in the Commons earlier.)

A stalemate wouldn't be a victory for the rebels.  But it wouldn't be a win for Gaddafi, either.  And as long as the west keeps watch on Libya, imposing the no fly zone if necessary, supporting the rebels with advice and assistance, and - I hope - ending the arms embargo if Gaddafi resumes violence, then he's doomed in the long run (whatever follows from the dramatic announcement of a ceasefire).  The Arab world will grasp the point and its rulers will get the message.   Slaughter protesters, and the west will act.  Its talk of democracy has content, after all.  And its values are better than Islamist clericalism.

This isn't the politics of neo-conservatism, with its abstract doctrine of using power to spread democracy.  This is the politics of a specific situation.  If Ben Ali hadn't been driven from Tunisia and Mubarak from Egypt, if there hadn't been protests in Jordan and weren't Saudi troops in Bahrain, Cameron's response might have been different, and the background certainly would have been - there would, for example, almost certainly have been no Arab League support for a no fly zone.  Cameron's risky but right decision has an on-the-hoof flavour.  It's the product of circumstances, not doctrine.  It's the foreign policy of "it depends".