The United States has acquired the unfortunate habit of giving security commitments to small allies as avidly as American GIs distributed chocolate bars to European children during the waning days of World War II. But while the generosity of those American soldiers earned the gratitude of a war-weary population, Washington’s latest venture incurs serious risks. That is especially true when the United States supports a small client state in that country’s dispute with a much larger, more powerful neighbor.

In an article over at the National Interest Online, I discuss the latest example: the Obama administration’s increasingly blatant backing of the Philippines against China regarding conflicting territorial claims in the South China Sea. Instead of remaining quiet on the matter, as prudence would seem to dictate, Secretary of State John Kerry ostentatiously weighed-in at the East Asia Summit on October 10 in Brunei, implicitly backing Manila’s position. That episode is merely the latest in a series of actions since 2011 indicating an escalating U.S. commitment not only to the defense of the Philippines under a long-standing bilateral treaty, but support for that country’s stance with respect to the South China Sea.

Chinese leaders no longer try to conceal their annoyance regarding Washington’s bias against Beijing’s position. When asked about Kerry’s remarks, Foreign Ministry spokesperson Hua Chunying contended that “non-parties to the dispute should respect the efforts by relevant parties involved to peacefully solve the dispute” through direct negotiations, “instead of doing things that could harm regional peace and stability.” She added that “if some country really wants to safeguard peace and stability in the South China Sea, it should stop stirring up waves.”

It is usually a bad idea for a great power to back a small, volatile ally in a dispute with a much stronger neighbor. Such allies then have a tendency to adopt a bolder stance—sometimes even an irresponsible one—confident that their powerful patron has their back. The Georgian government’s provocative military actions in 2008 against the Russian-protected secessionist regime in South Ossetia seemed motivated in part by the mistaken belief that the United States and NATO would deter Moscow from retaliating. Fortunately, Georgia was not a member of NATO, despite the Bush administration’s wishes on that score, so the United States was not obligated to get involved in the Russian-Georgian war.

Washington does not have the same luxury, however, if a confrontation erupts between Russia and any of the small East European members of NATO. That is not merely an academic concern, since there are some festering issues, especially between Moscow and the tiny Baltic republics. U.S. leaders foolishly put America’s security on the line to defend “allies” that provide little, if any, military benefit to the United States.

Washington has done the same thing in East Asia in an even more dangerous setting. In addition to the alliance with the Philippines, there is the bilateral alliance with South Korea and a less explicit but very real commitment to Taiwan’s defense under the Taiwan Relations Act. The former could entangle the United States in a war on the Korean Peninsula, while the latter has an even greater potential than the Philippines tie to embroil the United States in a nasty confrontation with China.

The United States should enter into alliances only when the benefits to American interests clearly outweigh any potential costs and risks, but most of Washington’s commitments to small allies don’t even come close to meeting that standard. National security should not be treated as if it were akin to collecting stamps or coins. Acquiring and supporting allies for the sake of acquiring and supporting allies is not only wasteful, it’s dangerous.