David Cameron, Barack Obama and Nicolas Sarkozy have stated their commitment to regime change in a joint op-ed piece published in the Times [2] (£), the Washington Post and Le Figaro [3].

It is the first explicit statement from the world leaders that they are seeking regime change in Libya (though it has been hinted at before). Noting the legal constraints on them, the leaders explain their position thus:

Our duty and our mandate under UN Security Council Resolution 1973 is to protect civilians, and we are doing that. It is not to remove Gaddafi by force. But it is impossible to imagine a future for Libya with Gaddafi in power. The International Criminal Court is rightly investigating the crimes committed against civilians and the grievous violations of international law. It is unthinkable that someone who has tried to massacre his own people can play a part in their future government. The brave citizens of those towns that have held out against forces that have been mercilessly targeting them would face a fearful vengeance if the world accepted such an arrangement. It would be an unconscionable betrayal.

In calling for Muammar al-Gaddafi to "go and go for good", the piece draws a line under previous suggestions of an immediate ceasefire and a negotiated exit for Gaddafi, or a divided Libya.

The first point to make is that Obama's involvement confirms US commitment to the mission. Adopting a cautious approach so far, it has handed control to Nato, and US fighter planes withdrew days in to the mission. The op-ed piece signals that the US is in it for the long haul. The Times reports that the article was initially penned by Cameron and Sarkozy, who sent a copy to Obama out of courtesy. He then asked to have his name added.

Second, it demonstrates frustration with the diplomatic efforts of the international community – and a response to domestic calls in all three countries for an "endgame"; a clear strategy for where the floundering mission is going. Three days of talks in the Gulf state of Qatar have come to nothing. Diplomats are now looking at ways to step up efforts in Libya while staying within the boundaries set by the UN mandate.

The article stresses that "it will be the people of Libya, not the UN, who choose their new constitution, elect their new leaders and write the next chapter in their history". But it is important to remember that, however nuanced the position put forward by the leaders may be, this is not how it will be received by the Muslim world.

I have just returned from a trip to Pakistan, where the received viewpoint among everyone I spoke to was that this was another Iraq, the west using any excuse to interfere in the region and get rid of Gaddafi just as it got rid of Saddam. Friends in Egypt tell me of a similar attitude.

It goes without saying that there are vast and important differences in this conflict: its legality, for a start, and the request by rebels for help. But now that regime change is explicitly on the table, the allies must be very careful about how they proceed if they do not with to diminish public support in the region even further.