Donald Trump's recent statements about Russia's war in Ukraine and his fixation on acquiring Greenland have sparked alarm and disappointment in the West.
The Kremlin's precedent, dating back to the Cold War, of attacking military allies is particularly troubling, especially when it comes to the US President's repeated claims that the US "needs" Greenland for national security and his refusal to rule out seizing it by force.
If Trump were to proceed, he might inadvertently follow the same path as the Soviet Union, which invaded its communist partners in Eastern Europe during its ideological and military confrontation with the capitalist West.
In 1956, Soviet troops invaded Hungary to crush a popular uprising that threatened to overthrow the communist regime in Budapest, resulting in the deaths of up to 3,000 people in street shootings.
In 1968, Moscow orchestrated an invasion, this time with other Warsaw Pact forces, to quash the Prague Spring led by Czech communist leader Alexander Dubcek, who introduced new freedoms aimed at creating "socialism with a human face".
Unlike Trump's potential Greenland invasion, the Soviet actions were not motivated by a disregard for the Warsaw Pact but rather to protect the integrity of the alliance. Hungarian leader Imre Nagy, who was executed later for his role in the 1956 uprising, attempted to defect from the alliance during the uprising.
Charles Kupchan, a senior fellow at the Council on Foreign Relations and former Obama and Clinton White House director for European affairs, noted that the Soviet Union's use of force was different because it was not involved in territorial conquest but rather in upholding the integrity of the alliance by propping up regimes that might defect.
Looking at NATO today, the idea of the US finding itself at war with a NATO ally is beyond imagination, given the alliance's unity and solidarity since the Cold War's inception.
To prevent such a scenario, Denmark could invoke NATO Article 4, which requires consultations among the alliance, signaling an imminent threat. If the US then attacked and Denmark invoked Article 5, which provides collective defense for other members, it could lead to a military confrontation between Washington and the rest of the alliance.
Kupchan dismissed the likelihood of such a "world gone mad" scenario, citing NATO's previous internal disputes, such as US threats against Britain and France during the 1956 Suez Crisis and fierce Franco-German opposition to the 2003 Iraq invasion, which did not escalate to military conflict.
However, if tensions were to escalate, the Soviet Union's behavior towards the Warsaw Pact could offer lessons for NATO.
John Lewis Gaddis, a Yale University history professor and biographer of George Kennan, the US diplomat who initiated the West's anti-communist containment strategy, pointed out that the Soviet Union's mistrust of its own allies was a precursor to its downfall.
Gaddis emphasized that the purpose of an alliance is not just to deter opponents but also to reflect the interests of its members, sometimes even the smaller ones. He argued that an alliance is much stronger when its members want to be part of it rather than being forced in by the greatest power.
These lessons can be applied to US interests in Greenland, where it has had military bases since 1941, established by Franklin D. Roosevelt as he prepared to join the British side against Hitler in World War II.
Gaddis noted that Greenland's strategic position could make it vulnerable to China or a resurgent Russia in the future, but maintaining and potentially expanding the existing US bases in Greenland through cooperation with the Danish government would be easier than creating unnecessary friction through unilateral provocation.
Trump's approach is simply creating unnecessary friction for himself.
