Leading article: The limits of intervention

The Paris summit yesterday of the 10-nation coalition of the willing, including the Arab League, backed by a United Nations resolution authorising the use of force to impose a no-fly zone over Libya, marks a triumph of diplomacy.

Inevitably, it is marred by the besetting fault of such negotiations: it has taken too long for the world community to come to this point. Nato could have declared a no-fly zone at the emergency meeting of the North Atlantic Council on 25 February. Colonel Gaddafi has exploited the further delay between the UN Security Council vote on Thursday and yesterday's meeting to pursue his murderous campaign against his own people. But that is the price of unity. Far better to have the Arab League call for a no-fly zone and the UN respond than to have the rich Western nations of Nato decide what is good for north Africa.

It was significant that China and Russia allowed the UN to authorise the use of military measures, abstaining in the critical vote. That means that the doctrine of liberal interventionism is still alive. It is an idea that this newspaper supports: our contention has always been that it requires the legitimacy conferred by the UN or by collective action to avert crimes against humanity. That is why The Independent on Sunday supported British military involvement in Kosovo and in Afghanistan – although in Afghanistan we argue that our mission is now unclear and that our troops should now be withdrawn more quickly than the Government plans. And that is why we opposed the invasion of Iraq: it lacked explicit UN authorisation, and was certain to unleash terrible destructive forces.

Of course, a no-fly zone is an imperfect sanction. Measured against the professed aim of UN Security Council Resolution 1973, "to protect civilians and civilian populated areas under threat of attack", it is already failing. Nor is it likely to do much to achieve the more strategic aim of helping the anti-Gaddafi forces – and we are not sure how savoury some of them might be – to take the fight to the dictator in his Tripoli bunker.

All it might do is constrain Gaddafi's ability to wreak revenge on his own people, much as the no-fly zones did in northern and southern Iraq between 1991 and 2003. Yet that is much better than nothing, because there was no repeat of the mass killings of Kurds or Marsh Arabs in Iraq after the no-fly zones were established.

And it is better that we should accept the shortcomings of a liberal interventionism that respects international law, rather than allow the impatience of "something must be done" to tempt us to precipitate military action that could lead to more bloodshed and suffering.

In every test of liberal interventionism so far, an air campaign alone has been deemed insufficient. It was not until Bill Clinton threatened to deploy ground troops in Kosovo that Slobodan Milosevic finally yielded. In Afghanistan the US-led coalition needed proxies on the ground, the Northern Alliance, and then allied troops to help to secure the country. But in Iraq it would have been better to continue to contain Saddam Hussein from the air and with the arms embargo, particularly since he had no weapons of mass destruction. And it is quite right that no one is seriously suggesting the use of Nato ground troops in the present case.

Barack Obama made it clear last week that US troops would not be deployed in Libya and the UN resolution specifically excludes "a foreign occupation force of any form on any part of Libyan territory". President Obama, incidentally, has been criticised in recent weeks for his apparent uncertainty and lack of assertion. We do not join in that criticism. It is wise that the United States should allow European and Arab states to take the lead in the Mediterranean theatre, while supporting the rule of law under the aegis of the UN.

It may seem anomalous that we should have supported the threat – and therefore the actuality – of ground troops in Kosovo but not in Libya. But it made a difference that Kosovo is in Europe, a province that expects one day to be part of the European Union. The lesson of Iraq is that Western troops on the ground outside Europe are likely to cause more harm than good.

The no-fly zone may seem inadequate to the task of protecting the Libyan people, but, however difficult it may be to accept, it may be that the best we can hope for is that the international community blunts the worst excesses of Gaddafi's brutality.