Ex-NATO chief warns Europe of 'post-Second World War order’ without the U.S.

As tensions rise over Greenland, concerns are growing that Europe could eventually face a future without the security guarantees of the United States. Rose Gottemoeller, former deputy secretary-general of NATO, warns that Washington's increasingly unpredictable behavior threatens the alliance and casts doubt on the U.S. nuclear umbrella over Europe.

Gottemoeller points out that Donald Trump's controversial statements about "acquiring" Greenland could mark a sharp break from the post-World War II order that has long guided transatlantic relations. This, she says, could push countries toward considering their own nuclear capabilities, potentially sparking a new wave of proliferation. Already, nations such as Japan, South Korea, and even some policymakers in Germany have begun debating whether they need independent nuclear deterrents.

The Trump administration has emphasized that Greenland, a semi-autonomous territory of NATO ally Denmark, is a strategic priority for the United States. Despite a clear joint statement from Denmark, Greenland, and several European allies including the U.K. affirming that Greenland “belongs to its people,” the White House insisted that "U.S. military force is always an option" to secure the territory.

Currently, the United States stores approximately 100 nuclear warheads across five NATO countries as a deterrent against external threats. Gottemoeller warns that any perceived weakening of U.S. commitment could undermine NATO's collective security, leaving Europe exposed and encouraging other nations to pursue their own nuclear arsenals.

According to Gottemoeller, the Trump administration seems intent on asserting dominance over the Western Hemisphere, signaling a return to a "might is right" approach. She argues that this undermines the post-World War II law-based international system established under the U.N. Charter, challenging decades of legal norms and collective defense agreements.

The situation has been further complicated by recent U.S. military operations in Venezuela, where American special forces carried out strikes against multiple bases and captured Nicolás Maduro. This move has raised fears that Greenland could be similarly targeted, despite its small population of under 57,000 and strong legal ties to Denmark.

Gottemoeller describes a worst-case scenario in which a U.S. military action against a NATO ally like Denmark would be not only unprecedented but an existential threat to the alliance itself. Such a move could position the United States as a hostile actor in Europe, eroding trust in NATO and its extended nuclear deterrent.

She also warns that this crisis could create openings for global powers such as Moscow and Beijing. Greenland’s vast deposits of rare earth minerals critical for advanced technologies and largely controlled by China make the territory strategically valuable. Trump’s interest in the island, she argues, is likely driven as much by these resources as by its geographic location, which is key for military and economic influence in the Arctic region.

In sum, Gottemoeller paints a worrying picture of a NATO weakened by U.S. unpredictability, a Europe that may need to rethink its security, and a global landscape increasingly shaped by the ambitions of both the U.S. and rival powers.