Joe Biden, in concert with American public opinion, soured on the long U.S. military disasters in Iraq and Afghanistan and finally withdrew U.S. forces from the two-decade disaster in Afghanistan, even though other prior presidents lacked the courage to carry out what was likely to be—and was—a messy exit. Yet one must not lose sight of the fact that the very experienced and effective president is a traditional foreign policy interventionist who believes that the United States should continue to lead the world through military actions and informal and formal security alliances, pledging to protect other countries.

In a recent speech, Biden reiterated his advocacy of an expansive global U.S. security umbrella: “American leadership is what holds the world together. American alliances are what keep us, America, safe. American values are what make us a partner that other nations want to work with. To put all that at risk if we walk away..., it’s just not worth it.” Echoing their leader, other U.S. officials claim that alliances are a bastion of a “rules-based international order.”

And recently, given Russian aggression against Ukraine, Chinese assertiveness in East Asia and the South China Sea, and Iranian and North Korean advancement of their missile and nuclear programs, other countries have flocked to attempt to take advantage of the U.S. government’s pledging taxpayer dollars to defend ever more countries or strengthen existing American alliance commitments. In the wake of the Russian invasion of Ukraine, Finland joined NATO, and Sweden is on the cusp of entering the alliance. With an assertive China in mind, Japan, South Korea, Australia, and the Philippines have enhanced alliance cooperation with the United States. Under the Abraham Accords, the United States agreed to sell high-tech weapons to Arab despots. Crown Prince Mohammed bin Salman, the effective ruler of Saudi Arabia, had implausibly begun to threaten to reorient the desert kingdom’s security relationship toward China, including arms purchases unless the United States signed a security agreement to defend Saudi Arabia if it was attacked. Finally, despite the United States providing more than $100 billion dollars in military, economic, and humanitarian aid to help Ukraine beat back Russia’s invasion, Ukraine’s President Volodymyr Zelenskyy is demanding NATO membership or that the United States and Europe develop an alternative security guarantee to assist the Ukrainians deal with the future threat from Russia.

Understandably, after the twin U.S. quagmires of Iraq and Afghanistan—just as happened after the debacle in Vietnam fifty years before—some on both the left and right in America are currently reluctant to pour tens of billions of dollars more into helping even informal U.S. allies fight wars. After all, these informal and formal alliances have been set up for the United States to defend other countries, not for other countries to defend the United States—especially given the vast discrepancy between American military capabilities and those of all other allies, particularly in the ability to project power. Thus, President Biden’s assertion that so many alliances enhance U.S. security is questionable; in fact, perhaps these commitments only increase dramatically the possibility that the United States could be dragged into unnecessary, non-strategic, and costly wars.

The huge destruction and replacement of war machinery and expenditure of expensive ammunition in a single war in Ukraine should make Americans ask if the United States, with a yawning $33 trillion national debt, is not overextending itself by pledging formally and informally to defend a growing plethora of countries worldwide. Today, assisting informal allies in two wars right now is straining the U.S. budget, much as the long brushfire wars in Iraq and Afghanistan added greatly to the existing mountain of American debt. In the future, if two formal treaty allies came under simultaneous attack in two different theaters, the United States would be required to respond to both—thus likely generating taxpayer-funded outflows that would make the huge expenditures in Ukraine pale in comparison.

After World War II, the United States accounted for 50 percent of global GDP; now it accounts for only about 15 percent. Yet the United States—to defend itself and fulfill its security commitments to all these countries—accounts for about 40 percent of global military spending. This is considerable American overstretch, especially when most of the countries the United States defends or is thinking about defending are wealthy, can afford to spend more on their defense but don’t because of the U.S. security umbrella, and could also band together against bigger threats such as China or Russia. Thus, the immense expense of aiding two informal allies during wartime now should make American taxpayers reevaluate alliance commitments and extensive overseas foreign military aid.