Donald Trump's actions, including his attempted acquisition of Greenland and criticism of Europe, have raised significant questions about the reliability of the United States as an ally, particularly concerning the nuclear umbrella provided to Europe in the event of a conflict with Russia. This uncertainty stems from Trump's unpredictable foreign policy approach, which has led European nations to re-evaluate their security dependencies and consider alternative strategies for their defense. The article suggests that these developments necessitate a serious discussion about Europe's own nuclear capabilities or enhanced security guarantees independent of U.S. assurances.