Ever since the United States became the world’s leading power at the end of World War II, Washington has emphasized the importance of having allies. Indeed, U.S. leaders have often seemed obsessed with that goal, even when many of those allies add little or nothing to America’s tangible strength. With the partial exceptions of Japan and the major NATO countries, most of Washington’s alliance partners throughout the Cold War were actually protectorates and client states rather than true allies. They were security liabilities, not security assets.

The situation has not improved much since the end of the Cold War. That point is all too clear with the so-called coalition of the willing in Iraq. As it prepared to overthrow Saddam Hussein, the Bush administration was desperate to portray the venture as a multilateral enterprise. The truth, though, is that it has been an overwhelmingly American-British mission from the outset.

Most of the other members of the coalition have provided support that ranges from extremely modest to pure tokenism. Indeed, several have provided no military personnel at all, merely giving endorsements of the mission. Most of the remaining countries have sent contingents of a few hundred — and often just a few dozen — personnel. At the peak level of support, the coalition (not counting the British) consisted of 37 nations and a paltry 30,000 troops. It is now down to 27 nations and fewer than 10,000 troops. Several long-time allies, including Spain and the Netherlands, have withdrawn all of their forces already.

Even when the commitments have been more substantial numerically, the military significance may be far less than it appears. For example, South Korea stationed 3,200 troops in Iraq, but it did so only after formal combat operations ceased. Worse, Seoul insisted that all its troops be stationed deep inside Kurdish territory, where there was virtually no danger of combat.

The South Korean deployment was a profile in courage, though, compared to the “contribution” that Japan has provided. First of all, Tokyo sent only noncombat personnel. Second, other coalition troops (primarily the Dutch) have had to provide security for the Japanese contingent. In other words, Japan’s participation did little to enhance the mission in Iraq; it merely created more potential targets to protect.

The allied performance in Afghanistan is only marginally better. America’s NATO allies agonized for months before sending a small peacekeeping force to maintain order in and around the capital city, Kabul. Only recently, after intensive prodding, have the allies agreed to expand that force and undertake peacekeeping missions outside the Kabul environs. Even then, the European governments stress that their mission is pure peacekeeping; they will not assist U.S. forces in fighting Taliban and al-Qaida units. As in Iraq, the allied presence in Afghanistan seems focused more on political symbolism than on providing a meaningful military contribution.

Washington pays curiously little attention to what real strengths existing or potential allies bring to the table. Consider the countries that the United States lobbied to join NATO during the alliance’s last round of expansion. We added such military powerhouses as Latvia, Lithuania, Estonia, Slovakia and Slovenia. Such tiny states are inevitably security consumers, not security producers. They add next to nothing to America’s already vast military power. Indeed, the Baltic republics, given their tense relations with Russia, merely create potential arenas in which the United States could become entangled in unnecessary wars.

It is a great curiosity that the nation that has the greatest degree of power in the international system since Rome is so obsessed with acquiring, maintaining and placating a network of small, largely ineffectual, and often indifferent allies. Alliances can sometimes be useful, but merely having allies for the sake of having allies makes little sense. Washington needs to adopt a much more realistic and calculating strategy.