Iran is a maritime power bordered by the Caspian sea to the north and the Persian Gulf and the Gulf of Oman to the south. It shares land borders with several troubled U.S. allies, including Afghanistan, Pakistan, Turkey and Iraq.
Its location in the center of Eurasia is particularly important for trade. About a third of the world’s oil tanker traffic passes through the Strait of Hormuz, which is bordered by Iran and Oman. At its narrowest point, this shipping route is just under two miles wide. Blocking it could lead shipments of daily global oil exports to drop by an estimated 30 percent.
In terms of conventional military strength, Iran is far weaker than the United States. But the country has long pursued asymmetric strategies that could allow it to inflict serious damage on U.S. interests in the region.
Iran’s Revolutionary Guard Corps, a force loyal to Iran’s supreme leader, Ayatollah Ali Khamenei, and separate from the regular military, has an external special operations arm known as the Quds Force that has helped build proxy forces in places such as Iraq, Lebanon and Syria. It funds militias such as Hezbollah, which is powerful in its own right.
Iran has used these type of groups to target Americans before. Earlier this year, a revised Pentagon estimate found Iranian proxy forces had killed at least 608 U.S. troops in Iraq between 2003 and 2011. Iranian proxies could cause havoc in Iraq and Afghanistan again.
Iran’s navy has a real advantage against the United States, too. It doesn’t need big ships or firepower to block off the Strait of Hormuz, for example, but could use mines or submarines to force a halt in trade.
U.S. war games have suggested that speedboat suicide attacks and missiles could be surprisingly effective against the American military. A 2017 report from the Office of Naval Intelligence found that the navy of the Revolutionary Guard, which is distinct from Iran’s regular navy and focuses on smaller and faster but still heavily armed vessels, had received more responsibilities to protect the Persian Gulf.