Finally, we can put a figure on the cost of military action against Libya: £260m. Liam Fox confirmed the amount in a written statement to MPs, revealing that the campaign itself had cost "in the region of £120m". Another £140m will have to be spent replacing missiles and other munitions if the mission is to continue at its present rate.
It's a blow to the government's credibility and particularly that of George Osborne. On March 22 the Chancellor told the Commons that the cost of military operations against Gaddafi would be "in the tens of millions, not hundreds of millions". This has now been exposed as a dramatic underestimate.
But more significantly, the cost of the mission undermines Osborne's previous insistence that "the cupboard is bare". It is harder for ministers to defend library closures, Sure Start closures and the rest when the government is spending hundreds of millions of pounds on a war far from home.
The coalition has sought to present many of its decisions (the VAT rise, the tuition fees increase, the abolition of universal child benefit) as "unavoidable" but today's news is a reminder that it has choices too. Given that the government spent £694.4bn in 2010-11, £260m is, as Jock Stirrup, the former chief of the defence staff, said on The World At One, "very small beer". But it's the perception that counts. Public support for the mission, already at a record low, is likely to plummet further.