And although tripwire-centered deterrence arguably worked against China in the Far East (and Soviet aggression against Western Europe), the North Korean regime looks qualitatively different. Chiefly, neither Kim Jong-un nor his father or grandfather ever showed much interest in establishing normal, peaceful relations with the United States—or for that matter, with any major country. Indeed, even independent of its missile and nuclear weapons tests, its record of aggression has been matched by few countries in recent decades.

An America First president would understand the urgent need to rethink completely an alliance whose price could soon make September 11 look like arm-wrestling matches. And he or she would view this vulnerability as even less acceptable because of the free riding so largely responsible. Seoul has promised to boost its defense spending as a share of its gross domestic product, but the goal is still only 2.9 percent—although it arguably has long lived in the world’s most dangerous neighborhood. Meanwhile, its economy is likely to have been the world’s seventh largest last year. North Korea’s is miniscule. Why can’t Seoul match the North’s bloated military man-for-man and tank-for-tank?

South Korea’s politics make it a problematic ally, too, as evinced by its foot-dragging on the deployment of a U.S. anti-missile system and the blasé views of much of its population about the North Korea threat—which no doubt partly explain its paltry military spending. Nothing is more understandable than South Korea’s desire to avoid a devastating conflict. But an America First president would recognize that the stakes for the United States now are simply too high to pay it much heed. This approach would also note the comparable ambivalence (for different reasons) marking China’s views about North Korea’s nuclear forces, along with Russia’s chortling from the sidelines at America’s predicament—along with evidence of sanctions-busting by both.

And the conclusion would be obvious: North Korea’s closest neighbors—except for Japan—seem ready to accept Pyongyang’s nuclear status. Therefore, why should the United States, located a world away, be more alarmed? The only reason is the tripwire—which also creates the only plausible reason for Kim Jong-un to risk his own country’s destruction via a nuclear exchange with America’s overwhelmingly superior forces. An America First policy would remove the tripwire, and allow the big, strong, wealthy countries of Northeast Asia to handle Kim Jong-un as they see fit. Remaining nerves in Japan (and South Korea) can be calmed with sales of conventional weapons, too.

An America Firster in the White House would also drop U.S. opposition to the Japanese and South Korean acquisition of nuclear weapons. Unlike the situation in Europe, nuclear-armed American allies in Asia would undermine the legitimate American goal of preventing the further proliferation of such weapons. But such a U.S. leader would understand that a nuclear Japan and South Korea are all but inevitable, precisely because extended nuclear deterrence against an adversary with North Korea’s increasingly intercontinental capabilities isn’t a credible enough foundation for their core security. Indeed, such concerns explain why public support for nuclearization is growing steadily in both countries.

Although less closely followed than developments in North Korea, China’s ongoing nuclear force modernization presents similar challenges to America’s escalation dominance in Asia—and would convince America First leaders that the country’s entire strategy toward the Asia-Pacific requires similar changes. Given that continuing to resist China’s regional expansionism increasingly risks a Sino-American war that also could trigger a nuclear strike on U.S. soil, an America First strategy would phase out the nation’s alliances and forward deployments throughout the region. Just as with Japan and South Korea, the United States should offer other former Asia-Pacific allies whatever conventional weapons they wish to buy—a step that could deter further Chinese muscle-flexing by raising the prospect of encirclement by well-armed neighbors.

An America First president would understand that the country’s European and Asian allies are major U.S. economic partners. But he or she would not balk at needed change for fear of losing American economic influence. Instead, this president would realize that evidence for crediting extended deterrence with creating major influence is difficult at best to find. Otherwise, would Japan and South Korea remain such difficult trade partners?

It is anything but coincidental that the Middle East has joined Southeast Asia as the scene of one of the worst failures of American internationalism. In both regions, internationalist leaders expended vast amounts of national blood and treasure to achieve their entire suite of goals—entailing the transformation of turbulent and even failed parts of the world into regions successful enough to resist hostile influences.

Southeast Asia stands today as an exemplar of economic development and relatively free government. Yet Washington never identified compelling, specific economic or security stakes for the United States that could remotely justify the sacrifices made decades ago on behalf of these aims.

The Middle East’s oil has long represented such a stake, and the emergence of terrorists capable of devastating attacks on U.S. territory created another. But the American goals of alliance building and eventual transformation have remained firmly intact despite abundant evidence that the ingredients for neither objective exist. Most Middle East countries, after all, are too internally divided and weak to serve as reliable allies—or to cohere in their current forms. And they seem hobbled by a culture that prizes scapegoating and vengeance over constructive action.

A domestic response is much likelier to contain the terrorist threat than “fighting it over there”—namely, “keeping them away from here.”

As internationalist foreign and defense policies have striven to push an existentially secure United States ever more deeply and broadly into the affairs of dangerous, increasingly dangerous, or marginal foreign regions, internationalist economic policies have striven to increase the dependence of an existentially self-sufficient country on a world of generally poorer, less stable, and often unfriendly countries. An America First international trade policy would reverse these priorities. It would dispense with neoclassical economists’ longtime dream of ever deeper worldwide economic integration producing the optimal global division of labor and output regardless of individual nations’ relative performance. Instead, it would aim to maximize America’s autonomy and relative performance.

The national security and political independence benefits of such approaches are well recognized, and of course defense-related products and industries are to varying degrees recognized as exceptions to free trade principles. In addition, although mainstream economists vehemently disagree, the records of post–World War II Asia and Germany represent impressive evidence for the economic advantages created by such mercantilism.

But so does the roughly first two-thirds of America’s own history—precisely because of the massive scale and impressive diversity of its economy that, if anything, are both even greater. It’s easy to see why these characteristics would suffice to create a substantial degree of self-sufficiency—albeit one that, according to mainstream economics, would purportedly sacrifice significant efficiency, consumer welfare and wealth in an absolute sense.

Additionally, the nation’s actual and potential diversity could well eliminate or greatly reduce these tradeoffs. After all, trade is thought to boost efficiency and therefore wealth-creation—along with raising quality and lowering prices—largely because it fosters more competition than any single national economy can generate.

No one can reasonably doubt that this extra competition would have a tremendous impact even on large national economies. But what about the impact on a national economy that turns out one fourth of the world’s total goods and services all by itself? Is the relationship one for one? That is, does the $56 trillion of global output generated outside America’s borders expose the $18 trillion American domestic economy to three times the competitive pressure that it creates on its own? Could the multiplier effect be greater? Why wouldn’t it be smaller? In fact, especially since much of the world economy is far less advanced industrially and technologically than the United States, why wouldn’t the competition multiplier generated by international trade be much smaller? And couldn’t it even be small enough to pale next to the economic and social dislocations caused by unfettered trade?

From the opposite standpoint, if any foreign competition is critical to creating and maintaining satisfactory competitive pressures on domestic producers, why have American inventors spurred so many major technological breakthroughs without any apparent pressure from abroad, ranging from the cotton gin and the telegraph to the integrated circuit to the Internet? Similarly, if foreign competition is crucial to quality, why are so many Japanese and South Korean brand autos so excellent?

Moreover, opening a domestic economy to foreign competition isn’t the only way to intensify competitive pressure. National governments can also ratchet up anti-trust policies.

As a result, an America First president would seek to expand existing trade only if and when: such moves would boost the nation’s growth on net; bring access to products and services that are either unavailable at home, or available only at prohibitively expensive prices; and that would significantly increase competitive pressure on domestic producers and service providers as long as these pressures come from entirely private sector actors.

Because actual and potential U.S. levels of self-sufficiency (at reasonable costs) are so high, because domestic opportunities to intensify competitive pressures are so readily available, and because as a result, the nation’s need to expand trade would be modest, an America First president would also recognize that the United States approaches global trade from a position of considerable strength. Further, he or she would understand the additional leverage America enjoys as the longstanding consumer of last resort in a world full of economies heavily reliant on net exports for adequate growth.