Barak Seener, a research fellow in middle eastern studies at the Royal United Services Institute (rusi), commented on David Cameron's letter:
"Cameron has taken the moral leadership which Sarkozy has followed and which Obama has yet to follow, to have military strikes from the air to remove Gaddafi.
"I think the letter will place pressure on other leaders to follow suit.
"There should be intervention through the use of air power."
- issue of the day