Evan Moore devotes a National Review Online column to Republican presidential nominee Donald Trump‘s troubling approach to NATO.

For the past 70 years, U.S. presidents have recognized that defending our national interests requires using America’s overwhelming economic and military power to support like-minded allies. This vision of a U.S.-led global-security order, perhaps best embodied by the NATO alliance, has not only prevented major state conflict since World War II, but has also supported a global system of trade that has led to unparalleled prosperity for all. In his interview with the Times, however, Trump dismissed the value of America’s global leadership: “We are not the same country and the world is not the same world . . . . We don’t have the luxury of doing what we used to do; we don’t have the luxury, and it is a luxury.” Trump should recognize that America’s international system of alliances is not a “luxury,” it is the prerequisite of peace.

Trump’s remarks became even more alarming when he said that, as president, he would condition defending our NATO allies on whether they have met the organization’s target of devoting 2 percent of GDP to defense spending. David Sanger of the Times asked, “Can the members of NATO, including the new members in the Baltics, count on the United States to come to their military aid if they were attacked by Russia? And count on us fulfilling our obligation?” In response, Trump replied “Have they fulfilled their obligations to us? If they fulfill their obligations to us, the answer is yes.”

Trump’s threat was crouched in a familiar refrain in which he described America’s global alliances as if they were mafia protection rackets.