"I know the outer world exists, and I'll be very cognizant of that, but at the same time, our country is disintegrating," says Donald Trump, who wants to "make America great again" by refocusing U.S. foreign policy to rebuild American strength from within. This idea comes not from a civil libertarian's respect for the constitution, but from his trademark exhibitionist belligerence. He's less Thomas Jefferson than George Jefferson, moving on up to win his party's presidential nomination.

Trump is no actual isolationist. He says he wants to build U.S. military might. He has floated the use of American ground troops in Syria, pledged to torture suspected terrorists, argued for increased use of drones and for "knocking the hell out of ISIS"--maybe even with nuclear weapons. Trump doesn't oppose trade. He wants to shred the "stupid" agreements of the past and bring his state-of-the-art negotiating skills to secure much better deals, all to restore America's lost prosperity and U.S. manufacturing jobs.

He sees most U.S. allies as weak at best and free-riders at worst. He denounces alliances and institutions that he says constrain U.S. action and cost the taxpayer too much money. He doesn't want to scrap the NATO military alliance--he just thinks France, Germany and others should pay more of its bills. Trump's go-it-alone approach is in some ways simply an extension of Bush era neoconservatism and the Obama administration's extensive use of drones and financial sanctions.

That said, Trump has raised important questions that speak directly to the anxieties of many Americans, and the Washington foreign policy establishment would do well to engage him. Allies are more at risk than we are. Europe is far more vulnerable than the U.S. to Middle East turmoil and Russian aggression. Japan and South Korea are much more at risk than the U.S. to Chinese encroachment and threats from North Korea. ISIS is a much larger threat to Saudi Arabia than the U.S., and Americans don't need Saudi oil nearly as much as they used to.

Nor are conservatives the only ones raising these questions. Supporters of Bernie Sanders don't expect their champion to offer a well-articulated foreign policy, because they accept his view that the future of Asia and the balance of power in the Middle East are far less important than questions of economic fairness at home. They insist that trade is bad for America, and even Hillary Clinton--who championed the Trans-Pacific Partnership deal as Secretary of State--now pays tribute to this view.