Take Trump Seriously About Greenland

The United States grabbing land from an ally sounds like the stuff of a Netflix political thriller. But every American should contemplate three realities about Donald Trump’s aggressive desire to acquire Greenland, a semiautonomous Danish territory. First, unlike his usual shtick, in which he floats wild ideas and then he and his aides alternate between saying he was serious and saying he might have been joking, he means it. The Danes seem to believe him, and so should Americans. When institutions begin planning based on the president’s directions, as the White House is now doing, it’s no longer idle talk.

Second, Trump is calling for actions that likely contravene American and international law. He is undermining the peace and stability of an allied nation, while threatening a campaign of territorial conquest. He refuses to rule out an unprovoked war of aggression, a violation of the United Nations Charter and an international crime that would be little different in kind from Russian President Vladimir Putin’s attempt to seize Ukraine. Finally, the almost-certain illegality of any attempt to seize Greenland against the will of its people and the Danish government means that if Trump directs the U.S. military to engage in such an operation, he could well precipitate the greatest civil-military crisis in American history since the Civil War.

How do we know Trump is serious? “One way or another,” the president crowed in his speech to a Joint Session of Congress last month, “we’re gonna get it.” A few weeks later, in case anyone missed the point, Trump told NBC: “We’ll get Greenland. Yeah, 100 percent.” Trump says a lot of strange things, certainly. He has mused about striking hurricanes with nuclear weapons, running for a constitutionally prohibited third term, staying in office even if he loses, and annexing Canada as the 51st state. But when a president publicly makes a vow to Congress to do something and then repeats that vow over and over, such statements are not trial balloons; they are policy.

And sure enough, Trump has followed up by sending Vice President J. D. Vance and his wife, Usha Vance, as unwelcome emissaries to Greenland. Vance—a neo-isolationist who apparently expresses opposition to the president’s plans only in Signal chats—has now embraced Trump’s old-school imperialism. Worse, Vance tried to press Trump’s case by boorishly criticizing Denmark’s relationship with the island, smarmily telling the Danes: “You have not done a good job by the people of Greenland.” (Imagine the reaction in Washington if a European leader came, say, to Puerto Rico, castigated America’s management of the commonwealth, and urged the island to sever ties with the United States.) But at least he promised that military force, which to gain Greenland would have to be directed against Denmark, a NATO ally, was not going to be part of America’s efforts.

Trump, true to form, short-sheeted his hapless VP the next day by saying that military force was not, in fact, “off the table.”

On Monday, The Washington Post reported that the White House has begun work on estimating the costs of controlling Greenland in “the most concrete effort yet to turn President Donald Trump’s desire to acquire the Danish territory into actionable policy.” Once these kinds of meetings start taking place in the White House, the next step is usually to send out orders to the rest of the American national-security establishment, including the CIA and the Pentagon, to begin planning for various contingencies.

Even if the American people supported direct aggression against our own allies—by a large margin, they do not—public opinion is not a legitimate excuse for treaty-breaking. Treaties are the law of the land in the United States, and the president’s Article II powers as commander in chief do not allow him to wave a monarchical hand and violate those treaties at will. Just as Trump cannot legally issue orders to violate the Geneva Conventions or other agreements to which the United States is a signatory, he does not have the right to break America’s pact with NATO at will and effectively declare war against Denmark. When George W. Bush ordered U.S. forces into combat against Iraq in 2003, some of his critics claimed that his actions were illegal, but Bush at least had the fig leaf of a congressional resolution, as well as a lengthy list of UN Security Council resolutions. Trump will have literally nothing except his insistent greed and glory-seeking vanity.

If the U.S. military is given direct orders to seize Greenland—that is, if it is told to enter the territory of another nation, pull down that nation’s flag, and then claim the ground in the name of the United States—it will have been ordered to attack an ally and engage in a war of conquest, even if no shot is ever fired. These would be illegal orders, because they would violate not only our treaty obligations but also international prohibitions against unprovoked wars of aggression. At home, the president would be contravening the Constitution: Article II does not allow the commander in chief to run around the planet seizing territories he happens to want.

At that point, every senior commander, from the chairman of the Joint Chiefs on down, has a moral obligation to refuse to accept or support such a command. Pauline Shanks Kaurin, a military-ethics professor at the Naval War College (where I also taught for many years) told me, speaking in her personal capacity and not on behalf of the Defense Department, that civilian leaders have “the right to be wrong,” but that if the United States moves against Greenland, especially if both America and Denmark are part of NATO, “senior military leaders have an obligation to advise against this course of action and resign if necessary.” Shanks Kaurin added that this obligation might even extend to a requirement to refuse to draw up any plans.

But what if the orders are less obvious? Trump long ago mastered the Mafia-like talent of making his desires evident without actually telling others to engage in unsavory acts. In that case, he could issue instructions to the military aimed at intimidating Greenland that on their face are legal but that are obviously aggressive.

Retired Major General Charles Dunlap, who served as the deputy judge advocate general of the U.S. Air Force and now teaches law at Duke, suggested that Trump could take advantage, for example, of the wide latitude given to the United States in its basing agreement with Greenland. The president, Dunlap told me in an email, could choose to engage in “a gross misreading of the agreement” and move a large number of troops to Greenland as “a show of force aimed at establishing a fait accompli of some kind.” Military officers are required to presume that commands from higher authority are legal orders, and so a series of directives aimed at swarming forces into Greenland would likely be obeyed, Dunlap said, “because of the potential ambiguity” of such directives “as well as the inference of lawfulness.”

In any case, Trump and Defense Secretary Pete Hegseth have taken important steps to ensure that no one is left in the Pentagon to tell them that their orders might be unlawful. All of the top military lawyers whose job is to provide independent legal advice on such matters have been fired. And, as Dunlap notes, courts are notoriously reluctant to get involved in such questions, which is why Congress must step in. “The military,” he said, “ought not be put in the middle of something like this.”

Americans used to take their presidents far more seriously. Before Trump, when a president spoke, his words instantly became the policy of the United States government—for better or worse. When President Ronald Reagan caught his own aides flat-footed by bungling a policy message during a press conference in 1983, for example, a Reagan-administration official later said: “You can’t say ‘No, he didn’t mean it’ or ‘That’s not really government policy.’ That’s out of the question.”

But those days are long gone. As a direct result of Trump’s many off-the-cuff ruminations and long stretches of political glossolalia, Trump has convinced many Americans not to take their president at his word until it’s too late. (Consider how many people, for example, refused to believe that he would impose massive global tariffs, a policy they can now examine more closely by the light of a burning stock market.)

I realize that this entire discussion seems like utter lunacy. War against … Denmark? But when the president says something, it’s policy. Trump insists that he must be taken seriously. Americans and their elected representatives across the political spectrum should oblige him.