The Washington Post is right to note that Iran’s threats to close the Strait of Hormuz in retaliation for possible new sanctions on its oil exports are in all probability empty posturing. Iran, after all, needs to send its own oil exports (for example to China) through the Strait. Closing it would hurt Tehran above all, while the UAE, Saudi Arabia, and other Gulf states could reroute some of their exports via pipelines.
There is also the fact that Iranian military action is unlikely to succeed–it would meet a devastating response from the U.S. Fifth Fleet and potentially from the armed forces of the Gulf Cooperation Council. In fact, the last time Iran tried this trick–that would be in the 1980s–it lost a “tanker war” against the United States. Tehran has certainly developed some fresh capabilities since, especially in terms of mines, cruise missiles, and speed boats–including probably suicide boats. All of that would make Iran a serious nuisance and might allow the Iranians to close the Strait temporarily. But there is little doubt that the Iranians
ultimately would come out on the losing end of any ensuing conflict. Moreover, by initiating military action, they would provide the U.S. just the excuse we need to bomb Iran’s nuclear installations.
In sum, Iran would be acting suicidally if it tried to close the Strait. That doesn’t mean that such action is out of the question; the Iranian Revolution has often harnessed suicidal impulses. But it is unlikely and should not deter the Europeans from proceeding with their plans to embargo Iranian oil.