On Wednesday, Defense Secretary Leon Panetta issued a warning to NATO allies that reducing military spending on both sides of the Atlantic will risk “hollowing out” the alliance’s capabilities. Panetta implied that Europeans cannot continue to rely on the United States for their security. Following former defense secretary Robert Gates’s comments in June, Panetta joins the long list of U.S. presidents, secretaries of defense and state, and innumerable lower-level officials who have pleaded with Europe to pick up the slack on military spending, provide for their own security, and close the gap in capabilities.

But Secretary Panetta’s speech also praised NATO for the mission in Libya and he extolled Europe’s leadership in the campaign: “The alliance achieved more burden-sharing between the U.S. and Europe than we have in the past…on a mission that was in the vital interest of our European allies.”

Relative to past NATO operations, it may be true that Europe contributed more in this instance. But this ignores the fact that the mission would not have been possible without the unique capabilities of the U.S. military. As Justin Logan pointed out, the Europeans quickly ran out of munitions and relied on the United States to conduct air strikes. “Thus, Washington essentially borrowed money from China to buy ordnance to give to Europe to drop on Libya.”

Panetta’s finger-wagging will do little to alter the incentive structure European states confront when determining what they should spend on defense. As I explain in an article recently published at Big Peace, until the United States takes concrete steps to force Europeans to spend more for their security, they will continue to free-ride on the U.S. taxpayers’ dime.

Cutting the Pentagon’s budget without imposing additional burdens on our troops requires getting our allies to do more. That is unlikely to happen unless U.S. officials, beginning with Secretary Panetta, force the issue. Unfortunately, he is merely one of many in Washington who seem to forget how incentives work:

Those who simply assume that others would not do more to defend themselves and their interests often ignore the extent to which U.S. actions have discouraged them from doing so. Just as some welfare recipients are often disinclined to look for work, foreign countries on the generous American security dole do not see a need to obtain military power. Our great power, and our willingness to use it, even when our own interests are not at stake, has allowed others to ignore possible threats, always confident that the United States will be there to rescue them.

The Obama administration’s rhetoric merely reinforces this message. The National Security Strategy, published in May 2010, declares “There should be no doubt: the United States of America will continue to underwrite global security.” Taking their cue, U.S. allies have proved understandably disinterested in military spending.

Despite Panetta’s pleas, U.S. strategy—and NATO’s very existence—allows this free-riding to continue. The Libya operation appears to have reinforced these destructive tendencies. If Washington really wants our allies to spend more to defend themselves and their vital interests, U.S. officials must jettison their reflexive attachment to the NATO alliance, an organization that has been irrelevant to U.S. vital security interests for at least two decades.

Secretary Panetta understands the United States is dealing with its own fiscal problems, but he has missed a perfect opportunity to offload a share of our burdens on to our rich allies.