Donald Trump speaks during a campaign rally at Pennichuck Middle School in Nashua, N.H., on Dec. 28. (Andrew Harrer/Bloomberg)
Opinion writer

The main focus of Donald Trump’s media coverage has been his populist disdain for elites. But his main focus has often been a strident version of American nationalism.

Trump has offered this explanation of his own ambitions: “The reason I’m thinking about [running for office],” he told the Conservative Political Action Conference in 2011, “is that the United States has become a whipping post for the rest of the world. . . . I deal with people from China, I deal with people from Mexico. They cannot believe what they’re getting away with.”

It is difficult to discern a foreign policy in Trump’s oeuvre of rambling, extemporaneous speechmaking and Twitter pronouncements. He usually communicates without a hint of actual argument. But there is some consistency to his various statements.

Trump believes that U.S. allies in Europe and Asia have become free riders that should defend themselves and pay their own way. He calls the U.S.-Japan Security Treaty unfair. In exchange for the protection of South Korea, he argues, “we get practically nothing.” Mexico is “ripping us off” and purposely sending us criminals. It must be compelled to pay for a continent-wide wall. Trump proposes to “tax China for each bad act” and has raised the possibility of a 45 percent tariff. Vladimir Putin, in contrast, should be given a free hand in the Middle East to go after Sunni radicals and other opponents of the Syrian regime. And the United States should focus on killing terrorists as well as targeting their families for murder, apparently on the theory that war crimes are a demonstration of super-duper toughness.

As Trump’s political prospects have improved, we are required to give these foreign policy views more serious analysis, which is more than Trump himself has done. When pressed on such issues in debates and interviews, he is utterly incoherent. A man who confuses the Kurds with the Quds Force (Iran’s expeditionary military force) hasn’t the slightest familiarity with current events in the Middle East. And it feels like we have, so far, explored only the fringes of his ignorance.

But it is the theory behind Trump’s threats that is particularly dangerous. He is not an isolationist, in the Rand Paul sense. He is more of a Jacksonian (in Walter Russell Mead’s typology) — preferring a strong America that is occasionally roused to kill its enemies but then returns home and avoids entangling international commitments. The United States, in this view, should vigorously pursue narrow national interests and seek to be feared rather than loved.

This conception of America’s international role was common, before America had a serious international role. A Gallup poll from 1937 showed that 70 percent of Americans thought U.S. intervention in World War I had been a mistake. In early 1940, as German intentions of conquest were clear, less than 10 percent thought the United States should send its military abroad.

But this view of America is as relevant to current affairs as political events in ancient Rome. “The great need today isn’t to ‘beat’ core allies such as Mexico and Japan, while working with Vladimir Putin,” George Mason University’s Colin Dueck explains diplomatically. “On the contrary, the urgent need is to constrain aggressors such as Putin while supporting core U.S. allies like Mexico and Japan.”

Less gently put, Trump would be a president who could not reliably tell America’s enemies from its friends. He contemplates actions such as weakening U.S. security assurances to South Korea that might invite war. (Recall the outcome in 1950 of Secretary of State Dean Acheson’s implication that South Korea was outside America’s “defensive perimeter.”) Trump promises actions — like forcing the Mexican government to fund the great wall of Trump — that are, in the formal language of international relations, loony, unhinged, bonkers. His move to impose massive tariffs against China would earn derisive laughter at the World Trade Organization; if he persisted anyway, it might blow up the global trading order and dramatically increase tensions in Asia.

A Jacksonian role for the United States is positively dangerous in a world where many threats — terrorism, pandemic disease, refugee flows, drug cartels — emerge in failed states and hopeless places. It has never been more evident that the success of America depends on an expanding system of free trade, free markets, democratic governance and strong alliances — upheld, in Asia, Europe and elsewhere, by American security guarantees.

Trump’s version of American nationalism without reference to American principles is Putinism by another name. And it is just one more way that Trump would sully the spirit of the nation he seeks to lead.

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