9. The US Invasion of Grenada (1983)
In October 1983, the United States initiated Operation Urgent Fury, a military intervention in Grenada, without prior consultation with NATO allies. This unilateral action strained relations, particularly with the United Kingdom and Canada, who were not informed in advance. The invasion exposed significant flaws in alliance communication and coordination, leading to increased distrust among member nations. The United Nations General Assembly condemned the operation as a “flagrant violation of international law,” highlighting the international community’s concerns over the breach of sovereignty (britannica.com).
