By: Kyle Rochefort
In early January, just weeks weeks before his inauguration, then President-Elect Trump held a press conference at Mar-a-Lago. During the session, he introduced for the first time the idea of renaming the Gulf of Mexico as the Gulf of America. He added that the change would be “appropriate,” and that the new name had a “beautiful ring” to it. Then, on January 20, he actually followed through, signing executive order 14172, titled “Restoring Names That Honor American Greatness,” which directed the Secretary of the Interior to “take all appropriate actions to rename as the ‘Gulf of America’ . . . the area formerly named as the Gulf of Mexico.” As of February 11, the change was reflected on Google Maps, at least domestically.
Not many took this idea seriously, especially those on the other side of the domestic political aisle. But President Trump clearly did, and he (for now) appears to have pulled it off. Is this illustrative of his sincerity regarding other, similarly polarizing ideas? At the same Mar-a-Lago press conference, Trump claimed that, for “economic security” and to “protect the free world,” he was considering an acquisition of Greenland. Trump first floated the idea in 2019 during his initial term, but his comments came with “varying degrees of seriousness.” This time, however, he refused to rule out the use of military force when asked directly and threatened “steep” tariffs on Denmark for failure to relinquish control of the territory.
Greenland’s Prime Minister, Mute Egede, has reiterated several times that Greenland is not for sale. So, what are Trump’s options? International law recognizes five ways to establish territorial sovereignty: occupation, accretion, prescription, subjugation, and cession. Occupation requires appropriation of a territory that is not already controlled by another sovereign, and Greenland is currently a Danish territory. Accretion and prescription are off the table because Greenland clearly cannot be classified as an expansion of existing U.S. territory by geological changes, and the U.S. has not exercised jurisdiction over Greenland at all, let alone for a “prolonged period.” Further, while Trump refused to rule out the use of force, a formal annexation, and thus subjugation, is unlikely. Even if Trump sent troops, annexation during a conflict does not establish a formal conquest, “which is a sine qua non for acquisition of title by subjugation.” Thus, if this happens, it will likely occur via cession.
Cession takes place when one sovereign, through a treaty with an acquiring sovereign, cedes control over a territory. When cession occurs, the people of the ceded territory become nationals of the acquiring country, as seen in the U.S. acquisition of several current territories including Puerto Rico, Guam, and the U.S. Virgin Islands. But again, there must be a treaty, which requires cooperation from Greenland. In other words, without consent from Greenland, the U.S. cannot acquire it without violating international law.
To see why, look no further than the UN’s founding document. Article 1(2) of the UN Charter makes clear that one of the “main purposes” of the UN is to “develop friendly international relations” through respect for the principle of self-determination. Additionally, Article 2(4) explicitly “prohibits the threat or use of force and calls on all Members to respect the sovereignty, territorial integrity, and political independence of other States.” Thus, in one sense, Trump’s refusal to rule out military action could be considered a threat in violation of Article 2(4).
The UN Charter is considered an international treaty, and thus an “instrument of international law” to which all UN Member States are bound. The U.S., among the UN’s founding Members, is of course no different. It, like all other Member States, is subject to claims before the International Court of Justice, which is “annexed to the UN Charter, and forms an integral part of it.” Further, according to Article 103, the UN Charter supersedes all other treaties and international agreements. Therefore, even if Trump proffered some other basis under international law in service of his Greenland agenda, the core UN principles described above would prevail.
This only means so much, however. On paper, the U.S. is bound to international law, and that law forbids what Trump is proposing. But Trump has proven that he will accomplish his goals, one way or another. He also does not come across as someone who intends to break the historic trend of U.S. leadership “shun[ning] treaties that appear to subordinate [U.S.] governing authority to . . . an international body like the [UN].” Basically, the U.S. has a reputation for disregarding international law—even that which it has ratified—and the bodies that enforce it whenever such law does not align with its current interests.
It is impossible to predict what Trump will do, if anything at all. His comments regarding Greenland could reflect a legitimate policy aim, or pure political gamesmanship. Either way, they underscore the practical reality of international law and power dynamics. If history and Trump’s track record are any indication of what is to come, whether the U.S. attempts to seize Greenland may not be a question of legality, but international enforcement bodies’ or other States’ abilities to effectively challenge such an attempt.
