'No agreement' on coalition's mission in Libya
The United States says it has made significant progress against the forces of Col Gaddafi, on the second day of air strikes on Libya by international forces.
Qatar says it will join the campaign - the first Arab country to do so.
Earlier, the Libyan government said it had ordered another ceasefire.
Nicholas Burns was US Under-Secretary of State under President Bush. He is now professor of International Politics at Harvard University.
The BBC asked him whether the coalition should have been more certain of the outcome it wants to achieve - before launching the no-fly zone.
21 Mar 2011