As the North Atlantic Treaty Organization celebrates its 60th birthday, there are mounting signs of trouble within the alliance and reasons to doubt the organization’s relevance regarding the foreign policy challenges of the 21st century. Several developments contribute to those doubts.

Although NATO has added numerous new members during the past decade, most of them possess minuscule military capabilities. Some of them also have murky political systems and contentious relations with neighboring states, including (and most troubling) a nuclear-armed Russia. Thus, NATO’s new members are weak, vulnerable, and provocative — an especially dangerous combination for the United States in its role as NATO’s leader.

There are also growing fissures in the alliance about how to deal with Russia. The older, West European powers tend to favor a cautious, conciliatory policy, whereas the Central and East European countries advocate a more confrontational, hard-line approach. The United States is caught in the middle of that intra-alliance squabble.

Perhaps most worrisome, the defense spending levels and military capabilities of NATO’s principal European members have plunged in recent years. The decay of those military forces has reached the point that American leaders now worry that joint operations with U.S. forces are becoming difficult, if not impossible. The ineffectiveness of the European militaries is apparent in NATO’s stumbling performance in Afghanistan.

NATO has outlived whatever usefulness it had. Superficially, it remains an impressive institution, but it has become a hollow shell — far more a political honor society than a meaningful security organization. Yet, while the alliance exists, it is a vehicle for European countries to free ride on the U.S.military commitment instead of spending adequately on their own defenses and taking responsibility for the security of their own region. American calls for greater burden-sharing are even more futile today than they have been over the past 60 years. Until the United States changes the incentives by withdrawing its troops from Europe and phasing out its NATO commitment, the Europeans will happily continue to evade their responsibilities.

Today’s NATO is a bad bargain for the United States. We have security obligations to countries that add little to our own military power. Even worse, some of those countries could easily entangle America in dangerous parochial disputes. It is time to terminate this increasingly dysfunctional alliance.