The following is a guest post from Caitlin Talmadge, a political scientist at George Washington University:
The past week has seen rising tensions between Iran and the United States over the narrow waterway known as the Strait of Hormuz, through which roughly 90% of the Persian Gulf’s oil is exported each day. Iran’s vice president warned that “not a drop of oil” would pass through the Strait if the United States adopted tougher sanctions, and the country’s navy chief echoed the threat, claiming that “closing the Strait of Hormuz for Iran’s armed forces is really easy…. Or as Iranians say, it will be easier than drinking a glass of water.”
But is that right? The question is important not only as Iran completes a major 10-day naval exercise in the Gulf, but also in the broader context of recent calls for military strikes on Iran’s nuclear facilities. Any closure of the Strait of Hormuz would cause oil prices to skyrocket, and even the anticipation of such closure or of conflict there has the potential to induce serious jitters in the world oil market. But does Iran really have the capability to halt the flow of oil out of the Persian Gulf over a sustained period of time?
I explored exactly this question in a 2008 International Security article, and the short answer is no — but both the United States and Iran should take care not to allow the current situation to escalate, as each still has the ability to impose substantial economic and military costs on the other. Iran does possess substantial littoral warfare capabilities, consisting primarily of mines, anti-ship cruise missiles, submarines, and small boats. This arsenal, combined with the Islamic Republic’s historic ability to produce highly motivated fighters, should induce a healthy respect for Iran’s ability to cause trouble in the Gulf. In particular, if Iran were able to engage in substantial mine-laying without being detected, it has the potential to create a thorny mine-clearing problem for the United States in the Gulf—one that could quickly lead to an outright war between the two countries.
That being said, a key variable affecting Iran’s ability to disrupt traffic in the Strait is how many mines it could lay prior to detection. Iran’s own recent threats, combined with Fifth Fleet’s vigilance, make the sort of stealthy attack I analyzed essentially impossible in today’s environment. Additionally, tankers are resilient targets, and they can use (and have used) alternative routes in and out of the Gulf besides the narrow shipping lanes closest to Iran’s shores.
There are also some recent signs that Iran itself understands the additional economic and political costs it would pay in the event that oil could not get out of the Strait. After all, Iran’s own economy depends on the ability to export oil and to import refined gasoline, as does the economy of one of its major international patrons, China. It is hard to imagine that aggression in the Strait would provoke anything but a strengthened international coalition against Iran —t hough it is possible that the regime sees domestic political benefits in the current crisis, or is intentionally using it as a way to drive up oil prices.
For its part, the Obama administration is not spoiling for a fight in the Gulf, and the president has avoided comment on the Iranian threats. But the U.S. Navy clearly trains and prepares for operations in the Strait. Furthermore, as other analysts have noted, in the event that the United States is forced to engage in such operations, attacking targets on the Iranian mainland would become tempting. In some scenarios, it would be militarily necessary simply to protect mine-clearance ships or other vessels in the Strait from Iranian anti-ship cruise missiles.
All of this is to say that naval confrontation in the Gulf would benefit no one. It would be bad for everyone, but worst for Iran, whose naval assets are scarce and not easily replaced—a lesson Iran learned the hard way in its last major naval confrontation with the United States, in 1988. With any luck, leaders in Tehran remember these realities. Certainly, their recent behavior suggests a desire to extract leverage by publicly making a threat rather than by stealthily following through on it.