NATO's mission in Libya ends today after seven months.

What it accomplished in the short term is described in superlatives both by US and European diplomats. Operation Unified Protector was "a true alliance effort,” says Ivo Daalder, the US representative to NATO.

“As good a war as it comes … with limited civilian casualties,” says Tomas Valasek of the Center for European Reform in London, citing the difference with other NATO operations in precision bombing. “There were no Chinese embassies hit in Tripoli [as in Belgrade, Serbia in 1999], no refugee convoys hit, no weddings that I know about [as in Afghanistan.]”

Yet whether the Libya operation is any kind of model – or a “one off” made possible by the circumstances of a potential humanitarian disaster in Benghazi – remains unclear.

To optimists, this is a moment for Europe to step up its support for the 60-plus-year alliance.To much of Europe the outcome in Libya is considered a clearcut victory. European countries, led by Britain and France, may even see the Libyan NATO operation as a model for future operations giving the US a background role.

There is, however, more skepticism of that in US military circles. The French get high marks from Pentagon officials for the first time in many years.

But NATO is an institution that doesn’t operate separately from the collective agreement of its members and leaders. For some in Washington, the perceived paucity of European might and resolve – only eight out of 28 NATO nations initially responded to the conflict – underscores what Mr. Valasek describes as “the appearance of a weaker European partner” in NATO.

Skeptics in the new postwar generations in Europe are unwilling in an era of austerity to wave much of a revamped NATO flag. And in some US circles, there are questions about why a small war took so long, and why allies at various points ran out of munitions.

Still, the level of European participation was a big change in NATO operations in Europe just over a decade ago. In Kosovo, the US conducted 90 percent of the strikes, and the other allies contributed 10 percent. In Libya, those figures were inverted, and the operation came with palpable support from places like the United Arab Emirates, Qatar, Jordan, and Morocco, as Mr. Daalder notes in The New York Times.

Thus far, there are no clear figures about civilian casualties in the UN-mandated operation designed to protect civilians. Some commentators argue that estimates, if any, should be released to counter claims made and reported in some anti-Libya intervention blogs and media about tens of thousands of casualties.

The NATO alliance helped liberate a country whose National Transitional Council leaders quickly opened up the question about whether Islamic rulings permitting polygamy should be revisited. European leaders don’t want to think that was part of any NATO liberation, and have said so in recent days.