Trump has called acquiring Greenland "an absolute necessity." He insists that he "would like to make a deal the easy way but if we don't do it the easy way, we're going to do it the hard way," and he has declined to rule out taking it militarily, though he appeared to do so on Wednesday at Davos. When America's European allies presented a united front against Trump's territorial ambitions, he announced that tariffs would be placed on "Denmark, Norway, Sweden, France, Germany, The United Kingdom, The Netherlands, and Finland… until such time as a Deal is reached for the Complete and Total purchase of Greenland." On Wednesday, Trump posted that, having reached a "framework of a future deal with respect to Greenland," he would no longer be imposing those tariffs."

Trump's threat of tariffs this time was not to protect American markets. It is the weaponization of America's powerful economy in an unprecedented attempt by the leader of NATO to violate the sovereignty of a NATO ally and annex its territory.

"Countries have to have ownership and you defend ownership, you don't defend leases. And we'll have to defend Greenland," Trump said. With that statement, Trump dismissed the entire reason for being of NATO. For over three quarters of a century, the United States and its NATO allies have promised to come to each other's defense without ownership. That is what an ally is.

If Greenland is the island rock that NATO could crash upon, NATO was already listing and in trouble. The trouble did not begin with Greenland, though Greenland could be the line crossed that exposes the critical condition of the alliance.

The cracks and divisions within the NATO alliance were already exposed by the war in Ukraine. While the U.S. approached the war from a more global grand strategy perspective, some of its NATO allies approached it from a more local perspective. The U.S. sought to enforce NATO's right to expand anywhere it wanted—even to Russia's doorstep—and weaken a key rival to its hegemony; some in Europe saw weakening Russia from a more personal, local defensive perspective.

While the Trump administration has made it a policy priority to end the war in Ukraine by aligning any agreement with reality, his European partners have undermined those attempts by pressing Ukraine to hold out for maximalist demands that had been long left behind by reality. Europe and the U.S. have different goals in Ukraine and different ambitions at the negotiating table. The cracks in NATO that are becoming critical in Greenland were first formed and exposed in Ukraine.