The international community has salvaged from the wreckage of the Iraq war its responsibility to protect civilians – that much is clear from the intervention in Libya. Here, Labour and the Conservatives have shown that on foreign affairs they are best when they are boldest, but both were at risk of succumbing to their own worst tendencies.

‘I don’t think we can stand by as Colonel Gaddafi takes greater hold of Libya’, Ed Miliband said on 14 March – his first clear indication that he would support a no-fly zone to assist the rebels. Libya has challenged western leaders in a way that even Egypt didn’t. In Labour’s case it exposed the tension between the two main pillars of its foreign policy under Miliband: values and multilateralism. Both are respectable, but given the international community’s divisions and morally diluting presence on the UN Security Council of Russia and China, they are not always likely to be compatible. The risk of values falling victim to sclerotic protocol was never far away.

The case for humanitarian intervention in Libya was so strong that, if it had not gone ahead, it would have shown that liberal interventionism was effectively dead. To its credit, the Security Council confounded expectations and gave the green light. The responsibility to protect was rescued from the clutches of the unilateralist, neoconservative right and progressives were spared having to choose between doing the right thing and the rule of international law. However, that tension still exists and bubbled over into Labour’s public utterances.

In the early weeks of the crisis, the party’s approach seemed driven more by considerations of procedural correctness than by what might help the freedom fighters win victory. When David Cameron first floated the idea of a no-fly zone, Labour rebuked him for shooting from the hip, with shadow foreign secretary Douglas Alexander praising US defence secretary Robert Gates’ criticism of the prime minister’s ‘loose talk’. Although Alexander did not rule out a no-fly zone, his recommendations in the Observer on 9 March were almost entirely devoted to soft power EU-centric alternatives.

Helping rebels overthrow a tyrant should have Labour written all over it, but the party’s caution can surely be attributed to its understandable determination to learn the lessons of Iraq. But have we learnt the right lessons? After all, the lack of a UN mandate was arguably the least wrong thing about that botched and unnecessary war. If the failure to get the correct sign-off made the Iraq war wrong, then we have to disown the Kosovo intervention, too. The success of an such action hinges above all on factors such as demonstrable need and a clear and compelling call for help from credible actors on the ground.

Both were present in Libya. Given the holes in the case for a primacy of multilateralism, could the importance attached to it by the post-Blair Labour party be symptomatic of something else – a lack of self-belief perhaps? After all, multilateralism gives you a reason to aim low and a ready-made excuse for failure. The trauma of Iraq must not, therefore, distort Labour’s foreign policy in the way that Suez did that of the Conservative party, when, in the following decades, large swathes of its members came to believe that foreign policy should be limited to an amoral pursuit of trade. Although not shared by Margaret Thatcher herself, it certainly was by the likes of Douglas Hurd and Malcolm Rifkind, culminating in the 1990s with the obstruction of US attempts to halt the bloodletting in the former Yugoslavia. Although multilateralism and Tory mercantilism seem polar opposites, they can both serve as a pretext for the abdication of responsibility and the delegation of judgements that politicians are too under-confident and exhausted to exercise.

Despite Iraq, Tony Blair’s interventionism was not an aberration from the progressive cause. Optimistic, impulsive interventionism has a long and often admirable pedigree on the idealistic left. The Bush-Blair bromance may not have been consistently admirable, but you can still detect even in Blair’s most disastrous adventures the same spirit with which Byron flounced into Greece and which the international brigades took with them to Spain. The real aberration would have been if, instead of the heirs to Blair, Labour’s ranks were to be filled with the heirs to Hurd.

Cameron and his Conservatives may not always think their ideas through, but on this occasion they stayed at least one idea ahead of us and shrugged off their ignominious heritage. Still, Miliband should be applauded for ensuring that Labour’s internationalism was not deformed by past traumas. His forceful endorsement of the Libya action on the day of the Commons vote showed that his thinking is not monopolised by Iraq, but incorporates the lessons of Kosovo and Sierra Leone. Once he had got past second-guessing the UN and deferring to the negativity emanating from the White House, Labour’s leader allowed himself to be guided by his own values and family history, and came into his own.