Coalition military action in Libya entered a new phase this week, with NATO taking over operational command and an international conference being held in London, David Tresilian reports from Paris Efforts were made to put the ongoing coalition military action in Libya on a new footing this week, with NATO taking over the enforcement of the no-fly zone established in the country under the terms of UN Security Council Resolution 1973 and overall operational command of the military strikes carried out by US, French and British forces. At the same time, an international conference bringing together representatives from some 40 countries was held in London on Tuesday in order to try to achieve consensus on the implementation of the coalition military intervention and to put an end to disagreement on how far coalition forces could go in enforcing the no-fly zone while respecting the terms of the UN resolution. According to a joint statement issued by British Prime Minister David Cameron and French President Nicolas Sarkozy before the conference began, its aims were to strengthen the implementation of Security Council Resolution 1973 and to "bring the international community together to support Libya's transition from violent dictatorship and to help create the conditions where the people of Libya can choose their own future." "Gaddafi must go immediately," the statement read. "We call on all his followers to leave him before it is too late. We call on all Libyans who believe that Gaddafi is leading Libya into a disaster to take the initiative now to organise the transition process." In a new development emerging after the conference, US Secretary of State Hillary Clinton began to talk for the first time of the US arming the rebels, something that she claimed could be legal even under the terms of existing UN resolutions. Resolution 1973, passed on 17 March and the legal basis for the coalition military intervention, authorises "all necessary measures to protect civilians and civilian populated areas under threat of attack in the Libyan Arab Jamahiriya, including Benghazi, while excluding a foreign occupation force of any form on any part of Libyan territory." While the US, Britain and France, the leading members of the coalition assembled to enforce the resolutions, have repeatedly called for Gaddafi to step down from power and for political transition in the country, Resolution 1973 does not authorise coalition forces to take sides in the civil war currently raging in Libya and it does not authorise regime change. There have been repeated criticisms since the coalition air strikes began on 19 March that the military actions designed to protect civilians from attack in Libya have gone beyond the terms mandated by the UN resolution and that therefore they could be illegal under international law. Turkey has been particularly vocal in its criticisms of coalition military actions in Libya, with Turkish Prime Minister Recep Tayyip Erdogan telling the country's parliament after the raids began that change in Libya should come about as a result of "internal movements and not of outside intervention" or "at the point of a gun." While the bulk of the missile strikes against pro-Gaddafi forces and military installations in Libya have been carried out by the US, with Britain and France playing supporting roles, the US has made it clear that it does not wish to lead what could be perceived as another Western military intervention in an Arab country. US President Barack Obama said in a speech on Monday that from the start he had anticipated that "America's role would be limited; that we would not put ground troops into Libya... and that we would transfer responsibility to our allies and partners." This week's decision to transfer responsibility for coalition military actions in Libya to NATO and the holding of an international conference in London to explore political ways forward came at the end of days of sometimes public disagreement among the coalition partners over the aims and methods of the military intervention. Not only have there been questions as to whether the US, Britain and France have gone beyond a limited interpretation of UN Resolution 1973, extending it to include de facto support for the rebel forces fighting the Gaddafi regime and therefore assisting in the process of regime change, but there have also been disagreements between coalition partners on who should be seen to lead the coalition actions and how these should be coordinated. At meetings held at the end of last week in Brussels, a compromise seemed to have been worked out under which the enforcement of the no-fly zone over Libya, a central component of actions carried out under Resolution 1973, would be given to NATO forces, while bombing raids against pro-Gaddafi installations and military forces would continue to be managed on an ad hoc basis by coalition members. While this week's London conference was designed to go some way towards agreeing on a common way forward that would stay within the bounds of Resolution 1973, it may not have silenced doubts about the ability of Britain and France to influence such transition consensually. In their joint statement at this week's London conference Cameron and Sarkozy encouraged members of the Libyan regime to defect, thereby isolating Gaddafi and helping to bring down the regime, and they called upon the Libyan population as a whole to "begin a national political dialogue leading to a representative process of transition." The scenario would suit the coalition well, since it would allow the thorny question of what to do if rebel forces continue to suffer defeats at the hands of pro-Gaddafi forces to be sidestepped, together with the difficult choices that would no doubt have to be made if the Libyan regime refused to fall.