Abstract
Along with the Strait of Malacca and the Singapore Straits, the Strait of Hormuz is arguably the most important bottleneck in international navigation because a large part of the global oil production needs to be shipped through this passage, which is only a few kilometers wide. In the context of the dispute about Iran’s nuclear program and new sanctions, Iran has threatened to close the Strait of Hormuz for international shipping, effectively cutting off many Western countries from important oil imports. In this article, the legality of such action as well as the legality of the mere threat to close the Strait of Hormuz are investigated. In addition to the International Law of the Sea, general rules of international law and the international law of armed conflict are taken into consideration. Particular emphasis is put on the sovereignty of other states, which is infringed upon by such threats on the part of the Iranian leadership.