For all the lamentation about the level of rhetoric in this Trumped-up election year, the race between Donald Trump and all-but-certain Democratic nominee Hillary Clinton is already shaping up to be a debate over America’s global role of the kind we haven’t had for decades, perhaps since the last “America First” movement of the late ‘30s. And it is a debate that some foreign-policy experts suggest is long overdue, even if it tends to distress U.S. allies around the world. ("The unthinkable has come to pass," Germany’s Die Welt wrote after Trump became the presumptive GOP nominee this week.)

It is also a debate that, were they still around to witness it, a majority of past U.S. presidents going back to George Washington would probably welcome—and most of them, believe it or not, might well take Trump’s side.

In his big foreign-policy rollout speech last week, Trump declared it was time “to shake the rust off of America’s foreign policy” and drop American pretensions about remaking the world in our image any longer. Or as he put it, in an obvious reference to the failed invasion of Iraq and intervention in Libya, America should abandon the “dangerous idea that we could make Western democracies out of countries that had no experience or interest in becoming a Western democracy.” Brazenly calling his agenda “America First”—never mind that was the name of the notorious pre-World War II isolationist movement—he also directly challenged the 70 years of bipartisan consensus over the post-World War II global order that America created. He suggested that the world needs America far more than the other way around, and he effectively warned U.S. allies that without a new global deal that demands a kind of tribute paid to Washington for its defense umbrella—he wants them to “prove” they are our friends, he says—he’d walk away from the world’s trade table, so to speak.

“We will no longer surrender this country or its people to the false song of globalism,” Trump said. “The nation-state remains the true foundation for happiness and harmony. I am skeptical of international unions that tie us up and bring America down.”

Predictably, Trump’s views have outraged commentators who lament the allusions to the prewar, anti-Semitism-laced isolationism of Charles Lindbergh and other members of the America First movement. His statements have also invited mockery from allies of Clinton, who as a pro-interventionist former secretary of state sees Trump’s turn away from the world as a naive and dangerous anachronism. Madeleine Albright, a mentor to Hillary on foreign policy and, as a refugee from Nazi Germany, a lifelong and passionate advocate of the idea that America is the “indispensable nation” in overseeing global order, accused Trump of historical illiteracy. “Maybe he never read history or he doesn’t understand it,” former Secretary of State Albright told reporters in a conference call organized by Clinton’s campaign.

Trump does appear to be giving short shrift to—and perhaps does not fully comprehend—a lot of the history that underlies America’s modern approach to the world. He doesn’t always make sense when he talks about foreign policy, calling at once for steadiness and unpredictability, a military buildup and a major war on ISIS but also restraint in the use of U.S. force overseas. In March, he embraced NATO in one interview and then declared it “obsolete” six days later. He speaks of upgrading “NATO’s outdated mission and structure—grown out of the Cold War—to confront our shared challenges, including migration and Islamic terrorism,” without appearing to understand that NATO has been engaged in that very enterprise for at least a decade, especially in Afghanistan. He is cavalierly dismissive of the international alliance-and-trading system that grew up in the ruins of World War II, and which many experts would say helped to win the Cold War and preserve American dominance.

He has also said things so offensive—openly embracing torture and other war crimes, such as killing the wives and children of terrorists, promising to ban all Muslims from entering the U.S. and to round up and deport every one of the 11 million illegals—that even many Republicans are horrified, saying such policies would undercut whatever moral authority America still has on the world stage. Some of his proposals, like imposing 45 percent tariffs on Chinese goods, could seriously disrupt or even destroy the world trading system, causing a global depression.

But Trump is also correct in suggesting that the current global system is an aberration in American history, that it may not be sustainable forever under current conditions, and that America should focus more on fixing our own economic house for a long time to come (a view shared, incidentally, by Barack Obama, who loves to say “it’s time to focus on nation-building at home”). The U.S. share of global defense spending has soared to more than a third of the total, while the American economy has dropped in size to one-quarter of global GDP; America spends more in total than the next seven largest countries combined: China, Saudi Arabia, Russia, Britain, India, France and Japan. And to what end exactly? No one can quite say. “Since the end of the Cold War and the breakup of the Soviet Union, we’ve lacked a coherent foreign policy,” Trump said in his speech. This is also arguably true. From Bosnia to Kosovo to Iraq, America has bounced around from idea to idea and intervention to intervention—from the idea of “humanitarian war” to the idea of “preventive war.” There is nothing even close to the ragged consensus that existed over Cold War containment.

So Trump may be an “id with hair,” as Hillary Clinton calls him, but at least when it comes to his foreign policy views, he’s an all-American id. His “America First” campaign theme has far deeper roots in the history of this country than most pundits are acknowledging. Indeed, Trump shouldn’t be dismissed as a mere apostate in his view of America’s role in the world; against the backdrop of all 239 years of America’s existence, he represents more a reversion to the American norm. Trump, in condemning one of the worst instances of American overreach in U.S. history, the Iraq invasion, declared in his speech: “The world must know we do not go abroad in search of enemies.” The line was an allusion to the famous injunction of John Quincy Adams in 1821 that America "does not go in search of monsters to destroy. She is the well-wisher to the freedom and independence of all. She is the champion and vindicator only of her own.” Adams went on to warn, somewhat presciently, America should know that “once enlisting under other banners than her own, were they even the banners of foreign independence, she would involve herself, beyond the power of extrication, in all the wars of interest and intrigue, of individual avarice, envy, and ambition, which assume the colors and usurp the standard of freedom. The fundamental maxims of her policy would insensibly change from liberty to force.”

Read today: Iraq. Trump is consciously invoking this tradition— hence his line about the futility of trying to forcibly transform nations, like Iraq—and the Adams allusion was quite intentional, a senior Trump campaign official told me. “Several sections of the speech were intended as a return to several foreign policy directives from our founding generation,” he said. Among them were a “Hamiltonian emphasis on having financial independence through manufacturing,” and “seeking to avoid complex foreign entanglements.”

Most modern internationalists, both Democratic and Republican, have long since relegated John Quincy’s injunction to history, that of a 19th century America that was still a developing country and wanted only to be left alone. The internationalists have been, until now, so dominant and sure of themselves and the postwar system that in recent years no one has questioned it (though the unilateralist George W. Bush administration did an effective job of largely ignoring its institutions—especially NATO—in its first term). Unwinding this system today is almost unthinkable: American power overlays every region of the planet, and it supplies the control rods that restrain belligerents and arms races from East Asia to Latin America (if not always successfully, as we’ve seen in the Mideast and Afghanistan). Nor does Trump appear to be going so far as to say he wants to withdraw from the global system—“To all our friends and allies, I say America is going to be strong again. America is going to be a reliable friend and ally again,” he said in his speech—but he does seem willing to renegotiate the terms and conditions for it, as well as America’s role in it.

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When Adams gave his “monsters abroad” speech, he was only channeling the fundamental beliefs of the Founders, starting with his father, John Adams, and his mentor, Thomas Jefferson, who warned against “entangling alliances” abroad. And of course George Washington, who wrote in his farewell address on Sept. 17, 1796 (though the actual words were probably drafted by Alexander Hamilton and James Madison): “Our detached and distant situation invites and enables us to pursue a different course. … Why quit our own to stand upon foreign ground? Why, by interweaving our destiny with that of any part of Europe, entangle our peace and prosperity in the toils of European ambition, rivalship, interest, humor or caprice? It is our true policy to steer clear of permanent alliances with any portion of the foreign world ... ”

Think about that: the Father of Our Country —with the imprimatur of Madison and Hamilton (he of the expansive view of federal power)—declared America’s “true policy” to be avoiding “permanent alliances” abroad. And yet that’s exactly what we’ve got 220 years after Washington’s declaration, tons of them—not to mention permanent membership in global organizations such as the United Nations and the World Trade Organization that we Americans had the largest hand in creating. Princeton scholar John Ikenberry, author of Liberal Leviathan: The Origins, Crisis, and Transformation of the American World Order, says that starting in 1946, the United States added a new ally—a nation with which it had some kind of security relationship—every five years or so. Today, it has a total of 62 permanent allies, including many from the former Soviet bloc. (Washington also has a fairly recent strategic partnership with India, another world power.)

Most historians and experts see this Western alliance system as a great triumph of American foreign policy (not least because it helped bankrupt the Soviet Union as Moscow tried to keep up with the more open Western economies), one that keeps delivering rewards. Thanks in part to this system, a quarter century after the Cold War, the U.S. still has no real challenger as the lone superpower of earth, and U.S.-created global institutions like the U.N., International Monetary Fund and WTO provide layers of multilateral cover that serve to take the raw edge off American hegemony, making it acceptable to much of the world. That is highly unusual in the history of great powers, which in the past have always provoked new rivalries and alliance-building against them. The overall prosperity created by this worldwide system, despite the inequities of globalization, has provided a powerful and enduring motivation for nations to remain part of it. In order to gain power and influence, countries must prosper; in order to prosper, they must join the international economy. Everyone inside this international system gets richer and stronger, while everyone outside it grows relatively weaker and poorer. Even Russia and China appear to realize this, which is one reason why Vladimir Putin’s fitful efforts to form a permanent “balancing” alliance with Beijing never amount to much, another boon to Washington.

But it is fair to ask, as Trump is, why we are simply continuing, through inertia and with little change, a system that was built up to thwart a set of threats that no longer exist. Maybe this vast, expensive global order was necessary against Hitler, and later Stalin, Khrushchev and Brezhnev—the very real threats of tyranny, totalitarianism and international communism in the 1940s, ‘50s, ‘60s, ‘70s and ‘80s—but is Putin’s Russia, or Xi Jinping's China, really enough of a threat to justify the same expense and effort? It’s also fair to ask—as Trump does, in his blunt way—whether U.S. allies have grown a bit spoiled and barely notice any longer who’s holding that defense umbrella over their heads, allowing them to continue massive spending on their welfare states. Even Obama calls them “free riders.” According to a report by NATO last summer—mentioned by Trump in his speech—only five of the 28 total NATO members are meeting the alliance’s goal of spending 2 percent of their gross domestic product on defense: the U.S. (at 3 percent of GDP), Great Britain, Poland, Greece and Estonia.

Trump is also questioning fundamental assumptions that no major party nominee-in-waiting (I’m not counting Pat Buchanan, Trump’s most recent ideological forebear) has seriously second-guessed for nearly 25 years: free-trade norms that were deployed against communist economies that no longer exist; the almost-religious assumption that globalization is always good, never bad. The flat-out opening of capital and labor markets to lower cost competitors abroad has plainly helped create an angry dispossessed middle class that no longer feels connected to their own economy. In his usual way this week, flirting with incoherence, Trump again promised a simplistic but enticing cure, declaring at a rally: “We will be the smart country from now on, not the dummies, OK? Not the dummies, because this is a movement that's going on.”

Translated, what Trump is calling for is nothing less than a return to an American normalcy that frankly has always been somewhat isolationist—or at least extremely leery of overinvolvement abroad. “America First” is Trump’s way dismissing what many Americans once viewed—and many still do—as a necessary evil: the entire globalized system of which America is in effect a guarantor. Trump would prefer to return home, unless we can make a profit by dunning our allies and trade partners.

In talking about a return to historical norms—“many Americans must wonder why our politicians seem more interested in defending the borders of foreign countries than their own,” Trump said in his speech—Trump is tapping into a powerful national myth, the tradition known as American Exceptionalism. This is the idea that America was—and still is—a glorious experiment in nation-building that must be kept apart from the corrupting influences of the world, especially those bad old Europeans; that America was conceived, uniquely in history, as an idea—an apotheosis of the best ideas about the rights of man coming out of the Enlightenment—and that God blessed the new nation with the luxury of conducting this grand experiment on its own continent with two broad oceans to protect it. As Thomas Paine wrote in “Common Sense” in 1776: “We have it in our power to begin the world again.” Abraham Lincoln also harked back to this founding mythology when he asked, in 1837: “From whence shall we expect the approach of danger? Shall some transatlantic giant step the earth and crush us at a blow? Never! All the armies of Europe and Asia could not by force take a drink from the Ohio River or make a track on the Blue Ridge in the trial of a thousand years. If destruction be our lot we must ourselves be its author and finisher.”

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Why are retreading all this old history and having this debate now? It’s not just the arrival of Trump on the scene; it’s also the mood he has tapped into—the reason his candidacy took off. Trump is exploiting much of the self-doubt already set into motion by the launching of a completely unnecessary war in Iraq, which seriously damaged the postwar alliance-and-trading system by grossly abusing America’s position within it. The Iraq War was made possible only because American governments after the Cold War had kept the mantle of “leader of the free world,” and George W. Bush convinced himself that his war was part of that tradition. It was not, and in the aftermath of that disaster a pendulum swing back to John Quincy Adams’ restrained “well-wisher” tradition was probably inevitable.

This could be a problem for Hillary Clinton—whom Trump has begun hammering, as Obama did before him in 2008, for voting to authorize the Iraq invasion—if it turns out that Trump has better captured the American temper. Clinton fully supports this global system and America’s oversight of it; she flew around the world several times as secretary of state to defend the just exercise of American power. According to Mark Landler’s new book, Alter Egos: Hillary Clinton, Barack Obama, and the Twilight Struggle over American Power, this isn’t just political expediency; she genuinely has the instincts of an interventionist hawk. She will no doubt continue to defend the system heart and soul, as will her husband, Bill Clinton, who was known in his time as the "globalization president.” (“There is no longer a clear division between what is foreign and what is domestic," he said at his first inaugural in 1993, and reiterated the point in his final foreign policy address in 2000; both sentiments now appear to be outdated in this time of Trump.)

The real question is whether, even if he wanted to, Trump could manage to tinker very much with a world system that appears to be a natural evolution of America’s rise to superpowerdom.

Hillary Clinton will have a good case to make. If a Trumpian America really did withdraw behind its oceans, what would we likely see unfolding overseas? Probably a restoration of the old power jostle that has sent humankind back to war for many millenia. Suppose, with the end of the Soviet Union, America had mysteriously disappeared as well, or more realistically had retreated to within its borders, as it had wanted to do ever since the end of World War II. Japan would likely have nuclearized and bid for regional hegemony with a nuclearized China. Europe would have had no counterbalance to yet another descent into intraregional competition, and lacking the annealing structure of the postwar Atlantic alliance may never have achieved monetary union. Russia would have bid for Eurasian dominance, as it has throughout its modern history and now appears to be doing again.

Most important of all, the global trading system, which the United States virtually reinvented after World War II, would almost certainly have broken down, killing globalization in its infancy. Perhaps that might have been good for some Americans, especially the manufacturing workers who have watched their jobs lost by the thousands to cheap overseas competitors. But most data show that globalization has created a far wealthier (if unequal) world overall. And the absence of a globalized, open economy in turn would have accelerated almost all of the above developments. A major war of some kind would be extremely likely. And given the evidence trail of the past century, the U.S. would likely end up being pulled in again—this time, to a conflict in a high-tech, nuclearized and very lethal age of warfare.

Instead, today, the American-led international system has managed to restrain the behavior of the next two great powers, China and Russia, through such institutions as the WTO and, yes, even the despised U.N. Security Council. China, for all of its aggressive behavior in its own backyard in East Asia, especially the South China Sea, has been a fairly benign player globally. It has cooperated in containing Iran’s nuclear program through the U.N., contributed to peacekeeping in Africa, and it has been prevented from declaring unity with Russia because of all its international trading interests, especially in the United States. Russia under Putin has also restrained its roguish behavior in spite of its move into Ukraine; it too signed on to the Iran deal and is negotiating in Geneva over a truce in Syria.

Clinton will argue all this—playing up her part in it, of course—and more. But if she’s perceived as too hawkish—and too much of a pro-globalization one-worlder—it still could hurt her at the polls. A new Pew Research Center poll finds that most Americans say it "would be better if the U.S. just dealt with its own problems and let other countries deal with their own problems as best they can," according to Pew. Surveys in recent years have shown a decided shift among Americans, a majority of whom now view globalization as a negative.

Whose view will win? There are limits to how much change a president can really effect, and inevitably even a Trump administration would probably maintain most of Washington’s now-entrenched role of global overseer. But it’s worth asking how much he would be able to pare it back or disrupt it—and whether a badly divided America can, or wants to, sustain this role forever. One thing is certain: Trump truly is standing on the shoulders of giants in questioning it. And perhaps it is long past time, given the warnings of our Founding Fathers (after all, they were right about a lot of other stuff), to engage in a true debate about the domestic costs of globalism.

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The real question is whether, even if he wanted to, Trump could manage to tinker very much with a world system that appears to be a natural evolution of America’s rise to superpowerdom. Oddly enough, it all came about as a historical accident. For most of America’s first century of existence, U.S. policy abroad was constrained by the Monroe Doctrine, which restricted U.S. intervention abroad (with the exception of the Barbary pirates) to the goal of preventing European intrusions into this hemisphere. That began to change with Teddy Roosevelt, but even he knew it wasn’t going to be easy. As he took office upon President McKinley’s death in 1901, TR was intent on becoming the first true internationalist American president, and he was perhaps the most traditionally imperialist-minded of presidents. Initially, he confined himself to reasserting the Monroe Doctrine, mainly in an effort to secure the new Panama Canal for trade and to rid the New World of lingering European claims in Cuba and Latin America (which had led to the Spanish-American War). When the first major global crisis of his tenure—the Russo-Japanese War in the Far East—erupted, he declared at first that America would remain neutral.

But the magic formula never appeared. Thus the global system we have today is truly a kind of accidental American empire.

But America had growing trade interests in the Pacific, having recently taken possession of the Philippines and a territory called the Hawaiian Islands, and Roosevelt was a keen student of geopolitics. He presciently predicted Japan’s victory over troubled Czarist Russia in 1905, and just as presciently worried about the small island nation’s growing power: “In a dozen years the English, Americans and Germans, who now dread one another as rivals in the trade of the Pacific, will have to dread the Japanese more than they do any other nation.” Worried about the rise of the Japanese in the Pacific, TR stepped in and negotiated the Treaty of Portsmouth between Japan and Russia. It was a first foreshadowing of the U.S. president’s arbitrator-in-chief role that would become familiar to later generations.

But Roosevelt, fearing like his predecessors excessive American entanglements, later retreated partially from East Asia, lamenting after the Philippine War “that America lacked the stomach for empire,” as historian H.W. Brands has written.

Still TR had cracked open the door to a new path in American history, and America’s gradual engagement in global, as opposed to hemispheric, politics proceeded in fits and starts from there. But again, it was cautious. TR’s successor but one, Woodrow Wilson, is still seen today, especially by conservatives, as a crusading idealist who led America down a path at odds with its interests and 19th century nativist traditions. In fact, like every American president before and since, Wilson was dragged reluctantly into the world. When World War I erupted in Europe in 1914, Wilson, like TR before him, at first responded in traditional American fashion: he declared neutrality. Later he proposed playing an arbitration role not unlike the one TR undertook in the Russo-Japanese war.

In 1917, German aggressiveness provoked America to enter the war in Europe, though there was more of a domestic motive than is often remembered: the notorious Zimmerman Telegram, in which Berlin pledged to help Mexico regain the American territory it had lost in 1848 in return for an alliance, was a key trigger. Bolshevized Russia also represented for the first time an ideological threat. That led Wilson to turn exceptionalism on its head; if America was going to get dragged into a world war, then it would “make the world safe for democracy,” Wilson said on April 2, 1917, in asking Congress to declare war. America would use the war to remake the world in its image so that dictators and monarchs couldn’t start another one. Ikenberry points out that the “paradox” of Wilson’s agenda was that “he wanted to avoid involvement in European politics, so he pursued a vision that entailed the utter transformation of European politics.”

Wilson, a former Princeton University president who had made his scholarly reputation as a political philosopher, knew he was treading on sensitive ground as he consciously sought to bridge the two American eras—the gap between Quincy Adams’ warning and what he, Wilson, saw as America’s emerging global world role. “You know that the United States has always felt from the beginning of her history that she must keep herself separate from any kind of connection with European politics,” he told an audience in England. “But she is interested in a partnership of right between Europe and America.” At another point, he reassured the U.S. Senate, “There is no entangling alliance in a concert of power.”

But at a time when many Americans are angry and feel dispossessed, and when they blame the rest of the world for their ills it may be that voters do want another choice.

But out in the heartland, and among their representatives in Congress, many Americans continued to believe that John Quincy Adams was still right. Wilson himself failed, finally, to impose a new international structure; his League of Nations went down to defeat in the Senate when Henry Cabot Lodge, chairman of the Foreign Relations Committee, refused to sign off on Article 10, which obligated all League members to intervene in the event of aggression against other members. Lodge’s objection, of course, was merely the old fear of entanglement, and his unilateralist justification for this stance was very much along the lines of the thinking of today’s unilateralism.

Thanks in part to Lodge—and to Wilson’s overreaching—American isolationism enjoyed a resurgence in the interwar years. The hapless Wilson died embittered, paralyzed by a stroke, to be replaced by a self-described “normal” Republican president, Warren Harding, who never brought up the League again (and was followed in succession by two other isolationist GOP presidents, Calvin Coolidge and Herbert Hoover). “We have torn up Wilsonism by the roots,” Lodge crowed after Harding won in a landslide. That was followed by other abject failures of international law, especially of the 1929 Kellogg-Briand Pact outlawing war. “The effort to abolish war can come to nothing,” Walter Lippmann wrote, “unless there are created international institutions, international public opinion, an international conscience which will play the part which war has always played in human affairs.” He was right, but American internationalism would lay dormant for another decade—until Dec. 7, 1941.

Like Wilson, Franklin D. Roosevelt decided that if he was going to get involved overseas he would correct the mistakes that Wilson made; he would do more than just create a League of Nations and he would fix the weaknesses in Wilson’s League. “We will not accept a world, like the postwar world of the 1920s, in which the seeds of Hitlerism can again be planted and allowed to grow,” FDR said. The U.N., with its Security Council designed around Roosevelt’s Four Policemen concept—the U.S., Russia, Britain and China each overseeing stability in their regions—was the first such attempt combining realist armed might with idealist international law.

Still, the U.N. always made the American right queasy, and even NATO was hardly a given. In the early days of NATO, the Truman administration pined for a self-contained European security pact that would allow the Americans to deemphasize or even unwind NATO, giving rise to Lord Ismay’s famous comment that the point was to “keep the Americans in, the Russians out, and the Germans down." Americans after the war, wrote historian Robert Divine, “yearned for a magic formula which would permit them to live in peace without constant involvement abroad.”

But the magic formula never appeared. Thus the global system we have today is truly a kind of accidental American empire. The question now is there really anything we can do about it, and should we really want to? Do we really want to alienate critical allies by driving a harder bargain with them at a time when China and Saudi Arabia are flush with capital to spend on their own alternative regional systems? “Nations have no permanent friends or allies, they only have permanent interests,” Lord Palmerston famously said. If America’s friendships and alliances have come to look permanent, perhaps that’s only because the United States has done a good job of convincing other nations that their interests are aligned with ours long term. The argument that Hillary Clinton will no doubt make is that especially in a post 9/11 world, a world in which both opportunities and threats have become globalized, the task of securing freedom, prosperity and safety—and American dominance—means securing the international system. She will insist there is no other choice.

But at a time when many Americans are angry and feel dispossessed, and when they blame the rest of the world for their ills—egged on by Trump’s rhetoric about getting “raped,” for example by China—it may be that voters do want another choice. Trump appears to be offering one, and a lot of people are listening.