The Strait of Hormuz has never been closed, but shipping has been disrupted in the past. The most well-known instance was the so-called Tanker War in the 1980s, in which Iran and Iraq attacked oil tankers during the Iran-Iraq War. International naval forces, particularly those of the United States and western European states, intervened to guarantee ships safe passage. Because of the width of the strait and the depth of its waters throughout, it would be difficult for a country to unilaterally close the strait for any prolonged period of time.