Vice President Joe Biden has become the Obama administration’s point man to reassure nervous NATO allies, especially those on Russia’s frontier, in the aftermath of Moscow’s seizure of Crimea. Following a trip to Poland, the vice president went to the Baltic republics. Standing side by side with the leaders of Latvia and Lithuania at a press conference in Vilnius, Biden reminded Russia that article 5 of the North Atlantic Treaty considers an attack on any NATO member to be an attack on all. He added that the United States was “absolutely committed” to defending its allies. “We’re in this with you, together,” he told the Baltic leaders.

Those comments confirm that U.S. policymakers have apparently forgotten NATO’s original strategic purpose. Indeed, they have apparently forgotten what the purpose should be of any U.S. military alliance: to enhance the security of the American republic. The commitments to NATO easternmost members threaten to do the opposite: greatly increase the risks to America for the most meager possible benefits.

Despite the diplomatic froth about trans-Atlantic solidarity and the promotion of Western values during the Cold War, NATO had a straightforward strategic rationale. It was a mechanism to keep a major economic and strategic prize, Western Europe, out of the orbit of an aggressively expansionist totalitarian power, the Soviet Union. That was a rational goal for the United States, especially given the global circumstances at the time. Adding Western Europe’s economic and military capabilities to those of the USSR would have drastically altered the global balance of power and created the specter of an isolated, beleaguered United States. American leaders were willing to incur even dire risks to prevent Moscow from making the region a satellite, however remote that outcome might seem to us in retrospect.

NATO’s relevance to the United States declined dramatically with the collapse of the Soviet Union. One cannot legitimately equate today’s Russia, with an aging, declining population, a military with many antiquated components, and merely the world’s eighth-largest economy, to the capabilities the USSR possessed during its heyday. Russia is a conventional, second-tier power that has some regional interests and ambitions, but it is not even remotely a global expansionist threat, much less a totalitarian expansionist threat.

That reality should have impelled the United States to give NATO a retirement party at the end of the Cold War, transferring responsibility for Europe’s defense to the principal European powers and, gradually, to the European Union. Instead, U.S. and NATO leaders scrambled to find an alternative mission to keep the alliance in business. They soon settled on an especially dangerous one—expanding NATO into Central and Eastern Europe, eventually to the borders of the Russian Federation itself. Critics warned that such a move created needless new risks for the United States, and that some of the commitments virtually invited a challenge from Russia once it had regained some strength. That is precisely what has happened, and Biden’s reassurances threaten to make a perilous situation even more so.

Although Soviet leaders might have harbored some doubts that the United States would risk nuclear war to defend Western Europe, that region’s importance made the U.S. commitment reasonably credible. In any case, it was simply too chancy for the Kremlin to assume that Washington was bluffing. But Washington’s current pledge to undertake such a grave risk merely to defend such tiny allies as the Baltic republics from a noncommunist Russia is far less credible. Those countries have little strategic or economic relevance to the United States. Conversely, because of historical and geographic factors, they have considerable importance to Moscow. That is a bad combination for the credibility of a U.S. defense commitment.

Vladimir Putin has already demonstrated that he will not cower in the face of U.S. geopolitical moves in Russia’s neighborhood. That point became apparent already in 2008, when Moscow responded to provocations in Georgia by launching a military offensive. The Kremlin did so even though Washington had increasingly treated Georgia as a de facto ally and spoke openly of pushing NATO membership for that country. Once fighting erupted, elements of the Georgian military and population apparently believed that NATO would come to their rescue. Except for imposing a few largely ineffectual economic sanctions, though, the United States tamely accepted Russia’s move to sever and protect two of Georgia’s secessionist-minded provinces.

The recent takeover of Crimea marked a significant escalation of Moscow’s determination to defend and consolidate its sphere of influence in Eastern Europe. This time, Putin not only scorned an implicit U.S. security relationship with a client state (as he did regarding Georgia) he openly defied repeated, pointed U.S. warnings. And again, the U.S. response has been anemic and little more than symbolic, suggesting that such warnings are merely a bluff.

Given that track record, it would not be a shock if at some point the Kremlin decided to press its interests regarding the Baltic republics. Russian-speaking inhabitants in both Estonia and Latvia (descendants of settlers sent by Moscow during the Soviet era) have long complained about discrimination at the hands of their governments. Putin has an ideal pretext if he wishes to try to pry those countries out of the Western orbit. True, it would entail a greater risk than his adventures in Georgia and Ukraine, given NATO’s explicit Article 5 security guarantees to members. But Putin has already shown himself to be a bit of a gambler.

Any Russian coercive moves against the Baltic republics would create an ugly choice for Washington between a bad outcome and worse one. The bad outcome would be to back down in the face of a Crimea-style action against a NATO member. That would be a humiliation for the United States and raise serious doubts about Washington’s other security commitments. A worse outcome, though, would be to try to fulfill the article 5 pledge and risk a catastrophic war against a nuclear-armed adversary over meager geopolitical stakes.

It was appallingly bad judgment for U.S. policymakers to put their country in such a position. Military allies are supposed to augment American power and improve the security position of the United States. The goal should not be to collect allies simply for the sake of collecting allies, regardless of the costs and risks involved. Acquiring an assortment of weak, vulnerable security clients masquerading as useful allies is the height of folly. They are dangerous strategic liabilities, not assets. Yet that is what Washington has done by pushing NATO’s expansion into Russia’s traditional sphere of influence.

Ted Galen Carpenter, a senior fellow at the Cato Institute and a contributing editor to The National Interest, is the author of nine books, the editor of ten books, and the author of 550 articles and policy studies on international issues. His books on NATO include Beyond NATO: Staying Out of Europe’s Wars (1994), NATO Enlargement: Illusions and Reality (1998), and NATO Enters the 21^st Century (2001).