Dozens and dozens of bombing sorties have already taken place over Libya and the allies are remaining tight-lipped over how long the campaign will last.
But in these times of financial austerity, questions have been raised over the cost of the operation. According to the Washington DC-based Centre for Strategic and Budgetary Assessments, maintaining the no-fly zone will cost some 353-million euros.
NATO, the British, Americans and French have already great experience of this type and a look at their previous operations may give some indication of what to expect financially.
In Kosovo for example, the four month exclusion zone cost some 1.3 billion euros. The no-fly zones over southern and northern Iraq for nearly a decade cost, on average, somewhere between 500 and 700 million euros a year.
Establishing an exclusion zone is also an expensive exercise. The Americans have fired more than 160 Tomahawk cruise missiles this week from their ships in the Mediterranean. Each one costs around 400,000 euros, while the air-to-ground AASM’s favoured by the French are worth somewhere between 300-350 euros each.
And what of the warplanes? Every hour a French Rafale spends in the air costs up to 13,000 euros without fuel charges. A Mirage fighter jet is slightly more economical.
Perhaps surprisingly, the larger B2 costs around 7,000 euros for every flight hour, but the radar avoiding bomber has to fly further to carry its missions from its Missouri base, and needs to be refuelled in the air, which does not come cheap.