Daniel W. Drezner is a professor of international politics at the Fletcher School of Law and Diplomacy at Tufts University and a regular contributor to PostEverything.

President Trump participates in a working dinner meeting with British Prime Minister Theresa May and Turkish President Recep Tayyip Erdogan during a NATO summit in Brussels in May 2017.  (Thierry Charlier/Pool photo via AP)

As president, Donald Trump does not exactly have a lot of core convictions beyond the greater glorification of Donald Trump. He does have certain instincts, however, and one of  them is that crude issue linkage can extract concessions in world politics. In Trump’s mind, his “maximum pressure” policy coerced North Korean leader Kim Jong Un to the bargaining table, for example.

As Will Saletan noted over at Slate, however, Trump is way fonder of coercing allies than adversaries:

Over the weekend, Treasury Secretary Steven Mnuchin seemed to confirm the notion that the Trump White House was using the steel and aluminum tariffs to leverage treaty allies into spending more on defense. According to the AP:

U.S. allies seeking to avoid the steel and aluminum tariffs approved by President Donald Trump might be asked to step up their financial commitments to NATO.

Treasury Secretary Steven Mnuchin told CNBC in a Friday interview that the president will consider national security, noting that Trump wants to be sure that NATO gets more funding from European allies whom Trump has previously criticized for not contributing enough.

“If we’re in NATO, he wants to make sure that NATO gets more money so that NATO can protect all of us and fulfill its goal,” Mnuchin said, underscoring Trump’s push to get NATO allies to pay 2 percent on defense. …

Other countries seeking exemptions from the tariffs will have to make their case through U.S. Trade Representative Robert E. Lighthizer, but the president will make the ultimate decision, a senior administration official told reporters Thursday.

And then there was this Trump tweet explicitly linking the tariffs to stronger security ties.

Let’s be blunt for a second: Trump has a lot of dumb ideas when it comes to foreign policy. NATO is not a membership club in which there are back dues if a country stops spending less than 2 percent of its GDP a year on defense. Contrary to his claims, trade wars are neither good nor easy to win, particularly against economic entities that are roughly the same size as the United States. Trump can talk about “taking the oil” from Iraq as often as he wants, it’s a completely impractical idea.

These are all mistakes, Donald. I looked them up.

So can Trump use America’s large market and disproportionate defense contributions to pressure the European members of NATO? American University’s Jim Goldgeier is pretty smart, and he doesn’t think so: “linkage didn’t really work with USSR all that well so not sure it will work with allies,” he tweeted.

I don’t think so either. But the reason I don’t think so is even more disturbing than you think.

See, contrary to Goldgeier, I concluded  in “The Sanctions Paradox” that threats of economic coercion can yield far greater concessions from allies than adversaries. That’s because allies do not anticipate frequent conflicts with one another. An ally making a concession now does not fear the material or reputational implications of backing down for the future. If conflicts between allies are rare, then a targeted state might choose to concede for the good of the alliance.

The paradox is that states are usually very reluctant to even threaten sanctions against their allies, for obvious political and policy logics. Coercing allies tends to put off other allies. Publicly threatening allies raises all kinds of domestic political costs for both sides. Finally, there is the very banal but important point that weakening an ally is really, really stupid in a world in which there are far greater threats. So the degree of asymmetric dependence ordinarily needs to be very high before one ally threatens coercion against another.

Trump clearly does not care about any of these risks, and that might be a bargaining advantage. It’s not completely crazy for him to think that he can coerce NATO allies into ponying up more on defense.

There’s a catch, however. Coercing allies only works if those expectations of future conflict remain low. If a targeted state starts to view the threatening actor as something other than an ally, then conflict expectations rise and the likelihood of concessions falls. This is why sanctioning Cuba in the 1960s did not work. Despite the severe economic costs, Castro decided to ally with the U.S.S.R. instead.

If Trump could convince U.S. allies that the current pressure represents an extraordinary exception to traditionally strong alliances, it is possible that he might get some concessions. Clearly, however, Trump has no love for either the liberal international order or the U.S. alliance system. He cannot even feign commitment to animating ideas of the open global economy or America’s security community. And our allies have noticed. So they are going to be expecting a lot more conflict down the road. This reduces their incentive to acquiesce in the present.

Furthermore, Trump is trying to coerce in the loudest, most visible way possible. In a world in which Trump has vaporized America’s soft power reserves, loud pressure will be more likely to generate resistance.

Trump is not as wrong about tactical issue linkage as he is about other aspects of his foreign policy. But he is mostly wrong, and he is also forcing every U.S. ally to question the future of the security relationship. This is a disastrous recipe for American foreign policy.