Does Iran boast the capacity to bar the Strait of Hormuz to commercial and naval shipping, as influential officials and lawmakers have repeatedly vowed to do? Doubtful – but Tehran can make serious trouble for the United States, the West, and its Middle East neighbors short of putting a stopper in the bottle of the Persian Gulf.
Just after the New Year, Iranian army chief Ataollah Salehi cautioned the nuclear-powered aircraft carrier USS John C. Stennis to stay clear of the Persian Gulf. “I advise, recommend and warn them over their return of this carrier to the Persian Gulf,” intoned Salehi, “because we are not in the habit of warning more than once.” The U.S. Navy paid these words little if any heed. Stennis remained in the area and was joined by its sister ship, USS Carl Vinson, in the Indian Ocean theater a few days later. Last week, after the European Union levied new economic sanctions to dissuade Iran from pressing ahead with its nuclear-weapons program, Muhammad Ismail Kowsari, deputy head of the Islamic Republic’s committee on national security, warned that the strategic waterway would “definitely be closed if the sale of Iranian oil is violated in any way.” Kowsari proclaimed that regional and Western navies would be unable to force the Strait should Iranian forces close it.
We have to allow for the bluster quotient in any pronouncement issuing forth from Tehran. Still, the Iranian armed forces possess sufficient seaward reach – in the form of anti-ship cruise missiles, speedboats and other small craft, sea mines, and so forth – to give Western capitals pause. The logic of “access denial” and “area denial,” two terms much in vogue among American commentators, involves manipulating perceptions among antagonists as much as it does girding oneself to actually fight battles on the high seas. Amassing and displaying the capacity to do significant damage sends a message. Tehran may believe it can convince Washington and its partners that persevering with sanctions will exact costs that vastly outstrip any gains the coalition can hope to extract from economic coercion. In effect, the Iranian leadership has threatened to hold hostage the 17 million barrels of oil that passes through the Strait every day, and the prosperity of oil-dependent economies with it.
As he usually does in matters of such gravity, Prussian theorist Carl von Clausewitz offers some sage counsel. Winning in competitive endeavors isn’t always about bludgeoning enemy forces into submission and imposing a favorable settlement. “Many treaties,” writes Clausewitz, “have been concluded before one of the antagonists could be called powerless – even before the balance of power had been seriously altered.” Belligerents often find “two other grounds for making peace” if they are unable to vanquish adversaries in combat. The “improbability of victory” sometimes prompts leaders to seek the best settlement they can. Or, the “unacceptable cost” of prevailing by force of arms can elicit a settlement. Issuing a credible threat to the sea lanes – credibility being a function of physical capability and the resolve to use it – represents Tehran’s way of trying to impose unacceptable costs on Western countries unless they abandon economic sanctions.
So in a sense, the debate over whether Iranian forces can close the Strait of Hormuz misses the point. Iranian mariners, pilots, and rocketeers can certainly menace shipping that passes hard by Iranian shores. In so doing they ratchet up insurance rates and oil prices, perhaps to unbearable levels. It doesn’t take much to give markets and maritime insurers the jitters. The Strait is only about 21 miles wide at its narrowest point, well within reach of shore-based missiles, artillery, and tactical aircraft. Confined waters, moreover, encumber the freedom of maneuver for large merchantmen and warships. Such “narrow seas” offer ideal hunting grounds for small craft and submarines not so encumbered. Mining the Strait is yet another option for Iran. Iranian engineers can manufacture certain types of advanced sea mines. The leadership has negotiated imports of others. Tehran doubtless learned from the Iraqi experience in 1990-1991, when Saddam Hussein’s military dumped hundreds of mostly crude mines into the Gulf, holding a US-led amphibious invasion force at bay off the Kuwaiti coast.
Such weaponry, in short, provides disproportionate bang for the buck. History is rife with examples when one combatant imposed high costs on another through minor actions at sea. Russian cruisers based at Vladivostok raided Japanese shipping halfheartedly during the Russo-Japanese War of 1904-1905, driving up insurance rates while taking a toll on sorely needed imports. Or, in today’s Indian Ocean, pirate attacks are little more than a nuisance in the Gulf of Aden, affecting only a statistically insignificant minority of shipping. Yet it prompted governments to dispatch naval forces and shippers to take expensive precautions like hiring private security firms to defend their vessels. Replicating these tactics is well within Tehran’s reach.
Will the Iranian threat persuade the West to cancel sanctions? I doubt it. There would be no better way to incur the enmity of the entire industrial world than to close the Strait of Hormuz, and Iranian leaders know it. But as political scientist Thomas Schelling points out, being seen as less than fully rational can be an invaluable asset in international interactions. The other side never quite knows what you might do! Schelling and Clausewitz probably wouldn’t approve of the goals of Iranian diplomacy. But they would recognize Tehran’s strategy instantly.
James Holmes is an associate professor of strategy at the U.S. Naval War College and co-author of Red Star over the Pacific. The views voiced here are his alone.

* Article publicat a The Diplomat. El creiem interessant per les seves reflexions sobre la situació al Golf Pèrsic