As people develop opinions about Libya they usually reason with historical analogies. To a historian, bristling with them, the temptation is especially strong – and dangerous. Thinking about invading Iraq, in 2002, was heavily influenced by analogies between that situation and the then apparent, recent success in Afghanistan. But the analogies were wrong. When that Iraq campaign was eventually salvaged, further supposed analogies strongly influenced new plans in Afghanistan. They were wrong again. Now, the mostly sour memories of those experiences, along with many other stories, colour thinking about Libya. Analogies are an excellent source of questions, but answers must be found in analysis of the case at hand, including its own history.

Muammer Gaddafi is a special case for the US. His direct involvement in the calculated 1988 destruction of the Pan Am 103 commercial airliner (killing 270 people) and the 1989 destruction of the UTA 772 commercial airliner (killing 170, including seven Americans) has recently been confirmed again, this time by his own ex-minister of justice. In the 1990s, the best that could be done about this was a tough set of sanctions.

Colonel Gaddafi raised the stakes, secretly buying uranium enrichment capability and a complete nuclear weapons design to add to his many tons of mustard gas, a weapon he had already used in action. In early 2003, with an invasion of Iraq imminent, he made a strategic choice to rebuild Libya’s ties to the world, which would require dismantling his weapons of mass destruction programme. Given the options at that time, the US, British and French governments made the best choices they could for their citizens’ safety. This WMD programme was no analyst’s conjecture; inspectors were surprised at the extent of what they found.

Now the US, French and British governments, among others, have publicly called for Col Gaddafi’s downfall. The goal is the right one. No honourable US government can forget or forgive a foreign leader who connived at the calculated mass murder of its innocent citizens. If this seems emotional, it is. But in the long run Americans will be safer if others judge that their government has a long memory and, if an opportunity beckons, will settle accounts. Also if Col Gaddafi’s regime wins its civil war, consider the next phase. There will be more massacres and refugees. What then? Indefinite containment and sanctions on a pariah state endowed with wealth, pathological leadership and experience in state use of clandestine terror networks?

There are the obvious issues of how such developments affect the momentum of events in the Arab world. But also imagine how an agonising spectacle of US passivity will ricochet politically and perhaps deform upcoming US choices about Afghanistan or Iran.

It is hard to gauge, from this remove, what the Obama administration really thinks about all this. The public image seems ambivalent, tangled in talks that may end up yielding mere gestures. Certainly the administration is preoccupied, not least by the terrible crisis in Japan and turmoil in Afghanistan and Pakistan.

But surely a lack of clarity about aims will reinforce the unease of military officers and perhaps even defence secretary Robert Gates. Under strain, they understandably shy from halfhearted cries for intervention in this particular part of the world unless the objectives and requirements are well defined.

An objective can be stated simply: Col Gaddafi out of power. Period. Libyans should choose their next leader as they wish. Any successor will understand well enough why so many, including the US, considered Col Gaddafi intolerable.

As for strategy, neither sanctions nor a no-fly zone may suffice. Col Gaddafi has hoarded cash and supplies for this very contingency. The momentum on the ground is driven by small mobile columns equipped with a few heavy weapons.

Most of the people and practically all of the military movement are within 50 miles of the Mediterranean. The military traffic relies on roads near the coast, with supply lines attenuated for hundreds of miles, supplemented by a few aircraft. The pattern is reminiscent of the warfare back and forth in Libya in the early 1940s. Nothing is more vulnerable to the modern western air power and precision-guided weapons available off that shore.

The task could be defined as more no-drive zone than no-fly zone, using strikes on the coast roads to confine the movement of Col Gaddafi’s mobile columns within designated areas. Most of the relevant road area does not appear to be protected by advanced air defences. Aircraft and warships of the US and other concerned states can field the needed capabilities.

It is unfortunate that Col Gaddafi’s forces have been allowed to recapture the key oil and gas nodes of Ras Lanuf and Zawiya. Reversing those gains would be the hardest military problem. Direct air assaults on Tripoli and Sirte should not be necessary. No western ground combat forces should enter Libya.

The other main purpose of outside assistance could be to help distribute imported necessities. Libya imports most of its food. Outside powers can ensure that Libyan oil and gas commerce sustains the future government of the country. As the ultimate outcome of the civil war becomes clear, Libyans could develop the terms of a negotiated settlement.

As for process, the keys are the Libyan National Council and Libya’s neighbours, Egypt and Tunisia. The Arab League has already been unusually assertive. Formal Nato co-ordination could help but is not obligatory. Nor should action by the UN Security Council be a prerequisite. The concerns are not universal. Col Gaddafi did not plot the killing of citizens in all those member countries; nor was he buying a nuclear weapons design with all of them equally in mind. In weighing the legitimacy of outside action, the views of Libyans and their neighbours take precedence: if it is not too late.

The writer is a professor of history at the University of Virginia. From 2005 to 2007 he was the counsellor of the US Department of State

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