Think of Ghadaffi's previous record: the Lockerbie bombing, targeted assassinations like in the 1970s, and attacks on US soldiers in Germany. Libya could in future represent a threat to Britain akin to al Qaeda.
So, the British government needs to think how it will deal with Ghadaffi MK II. Its policy should draw on past examples of containment and isolation. Libya's neighbours will have to be incentivised to bolster European - and especially Italian - attitudes. Britain, togther with Nato allies, will have to conduct Styxnet-style electronic warfare against the Libyan government. Britain will also have to seek to prosecute Libyan officials and arrest them if they leave the country. It will mean clamping down on all commercial links between Britain and Libya.
This is not a policy for the faint-of-heart. It is in fact a state of warfare. But just as Tony Blair had to accept that the Iraq War reduced Britain's stature in the world, so David Cameron will have to accept that his principled stance on Ghadaffi's crimes, but his unwillingness or inability to create a militarised anti-Ghadaffi coalition, means Britain will have a new and capable enemy in a post-revolutionary Libya. Robert Gates may worry that a no-fly zone over Libya represents a state of war. But the choice is not between war and peace. It is a choice between what kind of war the West wants to wage against Libya, for how long and with what consequences. For either way, a war is coming.