History is full of countries taking over other countries, but *how* a country is taken over matters a great deal, morally speaking.
By Eric Sammons
Crisis Magazine
January 24, 2026
President Trump wants Greenland. He wants it bad. He wants it so much that he's threatened military action (although he backtracked on that threat earlier this week) and he is willing to upend relationships with longtime allies to achieve his goal. But the question on everyone's mind is, Why ? And the additional question that should be on every Catholic's mind is, What is the morality of the United States taking control of Greenland?
Until very recently, Greenland was not on the forefront of any American's mind; in fact, it's likely most Americans couldn't point it out on a map, and many might confuse Greenland with Iceland. I would also wager that most people assume Greenland is part of Europe when in fact it is part of North America. The arctic country only has around 57,000 inhabitants, about the same number of people who reside in Sarasota, Florida, although its land mass is huge: three times the size of Texas. It's unlikely you'll see Greenland mentioned in many history books, as it has had minimal impact on the affairs of men over the ages, and it has had no real impact on the history of the United States. Yet now President Trump insists America's security rests on complete control over this obscure country.
The President has given a number of reasons for his campaign to take over the largest island in the world, including its natural resources and its supposed strategic military importance. The main focus in recent weeks of Trump's quest for Greenland is his assertion that it's vital to American national security. He claims that either China or Russia (or both) are threatening to take it over, and that Denmark-which is in charge of Greenland's defense-is not able to stop either country.
According to Trump, control of Greenland is essential to defending our interests, and a Greenland controlled by either China or Russia would be a disaster. In many ways, Trump is simply applying the Monroe Doctrine, since Greenland is part of North America and the Western Hemisphere and historically America does not permit European or Asian countries to control or even influence countries in its hemisphere (although Denmark, a European country, has ruled Greenland for centuries without American protest).
Trump's arguments, however, are weak. American global power is not exerted through territorial control, but by military bases throughout the world. And currently Greenland already hosts an American military base, and since Greenland is part of NATO (through Denmark), there's no reason we couldn't add a larger military presence on the island, including additional bases, without any changes to our current relationship with either Greenland or Denmark. The idea, in fact, that either China or Russia is preparing to take over Greenland is laughable on its face. Neither would directly threaten a NATO country, much less one with an American military presence and so close to our country. And even if something like that happened, America could quickly respond to the attempted takeover.
What about Greenland's natural resources ? Is the island a treasure trove of riches that America could use to its advantage ? Not exactly. The reality is that Greenland doesn't have the rich abundance of rare earth minerals as claimed, and the little they have isn't easily accessible. It's hard to argue that Greenland's resources are worth alienating our allies and upending our current world order.
So why is President Trump so insistent on taking over Greenland ? It's always hard to guess Trump's motives, as he often says and does things in an intentionally erratic fashion as part of his negotiation strategy. What he says on social media might not reflect his actual views. I tend to agree with the view that Trump simply wants to be a president who expands our territorial footprint. Remember, he's a real estate man at his core, and he sees land as the premium asset. He also looks at past presidents and seems to admire those who expanded the country and so wants to be on this list. To add Greenland, in his mind, would be a huge addition to the country, both literally and figuratively, and it would permanently put him in the history books as a president who grew the country.
Regardless of the reasons for Trump's actions, however, we must consider the morality of what he is doing. As Catholics, we can't simply go along with any action our government takes; we must evaluate those actions on the basis of Catholic morality and determine whether they can be legitimately supported.
First, it should be noted that history is full of countries taking over other countries by all sorts of means, from military invasions to arranged royal marriages. There are no fixed national boundaries-and never have been and never will be-that must be considered sacred and inviolate. Countries come and go, and countries change size all the time. Since World War II (and mostly because of it), we've experienced relatively stable national boundaries around the world over the past few decades, but that is an exception, not the norm. So the idea of America taking control of Greenland is not, in and of itself, in any way immoral.
That being said, the details of how a country is taken over matters a great deal, morally speaking. Every reasonable person today would agree that the methods used by Adolf Hitler to take over Austria, Czechoslovakia, Poland, and other countries were not morally permissible. At the same time, the divestiture of the Soviet satellite countries in the early 1990's is an example of a peaceful, moral changing of national boundaries.
In the case of Greenland, any military action taken by the United States to control that country would be clearly immoral and would not satisfy the conditions of Just War Theory. No matter how much one values NATO (I value it little myself), we currently have a good-faith treaty with NATO countries to defend any attack against a current member, which implies that we ourselves agree not to attack any current member, including Greenland. We could of course leave NATO and its treaty obligations, but as long as we are in NATO, attacking another member should be off the table.
Even aside from treaty obligations, it's simply not morally permissible to invade another country without very serious reasons, and no rational person can think the reasons currently given for invading Greenland-if true-meet that standard. There's no imminent threat to American security and there are many other peaceful alternatives that can be sought aside from military action. The archbishop of the U.S. military services, Timothy Broglio, even stated that it would be morally permissible for American troops to refuse to participate in such an invasion. It would be the height of hypocrisy to, for example, criticize Russia for invading Ukraine while trying to defend America invading Greenland. If anything, Trump actually has less justification than Putin.
That being said, we all know that Trump's threats of military invasion might have just been posturing to get a better deal from the Danes and NATO. We don't yet know the details of the framework for the deal that was announced this week, but most talk of America taking over Greenland revolves around our country simply buying the island from Denmark. Considered in a vacuum, this could be a course of action that doesn't violate any moral principles. But of course the devil (and potential immorality) is in the details.
First, would Denmark selling Greenland to America violate the sovereignty of Greenlanders ? What if the people of Greenland don't want to be a part of the United States ? It's not completely clear (at least to me) what rights Greenlanders have in regards to whether or not Denmark can transfer control of the country to another country. Currently Greenland is in a semi-independent partnership with Denmark in which Denmark provides money and defense, while Greenland manages its own domestic affairs. Can Denmark just sell that role to the highest bidder without first getting agreement from Greenlanders ? And if they did, would the relationship remain the same, or would America want more control than Denmark currently exerts ? These are questions whose answers can impact the morality of the agreement.
There's another factor, however, to be considered. This potential deal currently has all the characteristics of a mafia arrangement: You'll sell Greenland to us if you know what's good for you, right, Denmark ? The looming threat of a possible American military invasion nullifies any sense of a free decision by either Denmark or Greenland. Just as the store owner must agree to mafia "protection," so too Denmark (and all of NATO) is put in a situation where "no" isn't an acceptable answer. Further, the overwhelming power of America creates a huge negotiating imbalance, which can force Denmark to accept an unreasonably low price for the island. This might be good for getting the best deal for America, but that doesn't make it moral.
The ideal situation, from a moral standpoint, would be for the decision to be put up for a vote among Greenlanders. Allow them to freely decide. This type of process is something America has long touted as the proper path for nations around the world, as we constantly defend the rights of citizens to democratically determine their future. Yet in this case it appears such self-determination is not on the table if America really wants to take control.
Whether or not taking control of Greenland is in America's strategic interests is a question open to debate-it's a prudential decision on which people of good will can disagree. However, the morality of how America gains control of the island is less debatable: the Church has laid out clear guidelines in her moral teachings to this effect, and many of the paths President Trump has considered clearly violate those guidelines. I'm hopeful that the framework announced this week takes a moral path. As American Catholics, even if we support the annexation of Greenland, we should only do so if it's done in a moral manner, no matter how badly Trump wants it.
This article was originally published on Crisis Magazine.