With populism running wild in Europe and in the United States—the Brexit and American presidential candidate Donald Trump questioning U.S. alliances being just two obvious examples—suddenly people are asking the big questions about the future of Western institutions that should have been asked after the Cold War ended. Both the Brexit and Donald Trump seem to be driven by a nativist element, but that doesn’t diminish the value of the implicit questions that they are posing. Americans should listen to Donald Trump, while examining the Brexit, and ask themselves if the United States shouldn’t withdraw from NATO and other military alliances.

Of course, such a U.S. withdrawal would be much more consequential for NATO and other U.S. alliances than is the Brexit for the European Union. Britain is not even the largest economy in the EU. The United States accounts for three-quarters of the defense spending of NATO countries, and it is very unlikely that those allies—all much closer to zones of conflict than is the United States—will be defending the superpower rather than vice versa. Since World War II, the United States has provided security, formally or informally, for an ever-widening number of ever more prosperous nations in Europe and East Asia, but has gotten few commercial or other considerations in return. Many of these nations or blocs have not ever fully opened their markets to U.S. trade, finance, and investment.

Such one-sided alliances were justified by American elites and the foreign beneficiaries of such security welfare as being in the American interest too. Really?

George Washington, who preferred neutrality as a foreign policy, warned against the United States forming “permanent alliances,” and Thomas Jefferson cautioned against getting bogged down in “entangling alliances.” In fact, Jefferson wrote in 1799, “I am for free commerce with all nations, political connection with none, and little or no diplomatic establishment. And I am not for linking ourselves by new treaties with the quarrels of Europe...”

But times have changed, right? Rapid advances in communication and transportation have led to a more interdependent world, which compels the United States, as an exceptional nation in world history, to monitor disturbances in faraway and even insignificant places, so that they don’t snowball into larger threats—for example, the rise of another Adolf Hitler to threaten Europe. Thus, shouldn’t the views of America’s founders on foreign policy go the way of the powdered wig?

No, the basic geography of the United States hasn’t changed from the time of the nation’s founders; they perceptively realized that the United States might just have the most favorable geography of any great power in world history. The United States has two large ocean moats and is far away from the zones of conflict in the world. Today, the country actually might be even more secure than at the founding, because it no longer has foreign great powers prowling around its borders, but instead has weak and friendly neighbors, and now has the most capable nuclear arsenal on the planet—which should deter attacks, nuclear or conventional, from any nation with a home address vulnerable to cataclysmic retaliation.

As for interdependence, in the security realm, the advent of the nuclear age may have actually made the world less so; cross-border aggression—conflicts that have a greater potential to adversely affect U.S. security than do foreign internal civil wars—has dropped significantly in the post-World War II era. Alliances are not ends in themselves; they are used by countries to increase their security by banding together against foreign threats. Yet, after World War II, the United States began to acquire the first permanent alliances in its history just when it began not to need them—it had just developed nuclear weapons and ever since has been the leader in such technology.

But what about guarding against what a future Adolf Hitler or Joseph Stain could do in Europe? Ever since World War II, America’s overly interventionist foreign policy has been based on avoiding another Munich 1938 disaster, when British Prime Minister Neville Chamberlain appeased Hitler, instead of confronting him, thus emboldening an attempted German takeover of Europe. However, such a limited reading of history self-servingly absolves the United States (and Britain and France) from having created the Hitlerian monster in the first place. The United States entered World War I, tipped the balance to British and French allies that simply wanted to greedily expand their empires, declared that the Germans were guilty of starting the war, imposed harsh financial reparations on Germany that helped cause the bad economic conditions that brought Hitler to power, and demanded the abdication of the German king, thus clearing the way for Hitler’s rise and World War II.

One other important lesson from World War I is that alliances—even informal ones, such as the one Britain had with France and the biased U.S. “neutrality” of U.S. arms sales and financing credits sent to Britain but not Germany—can impede flexibility and drag countries into wars they don’t want. No one country desired World War I, but such webs made it spread and engulf the entire continent and beyond. And World War II was just World War I, Part II.

So with the Brexit and the Trump candidacy leading to an examination of the big questions, maybe the United States should ask whether its expensive alliances are really needed for security or are just to maintain an entangling and costly world empire based on vanity. Perhaps an Amerexit from them is in order.