How long can Iran keep the Straits of Hormuz closed?


How long can Iran keep the Straits of Hormuz closed?
by Ari Siletz

Looking for an informed analysis of a scenario where Iran closes the Straits of Hormuz, I found a paper by George Washington University’s Caitlin Talmadge. The young political science professor--who wrote the paper in 2008 when she was a PhD candidate at MIT--once talked down a Toyota dealer from $14000 to $9000, so I figured she must be savvier than most because I usually pay what the dealer asks for and thank him for being my buddy. Still, I had figured out all by myself that the military challenge in blocking the Hormuz is all about naval mines and anti-ship cruise missiles (honar kardam!).

In her detailed analysis of Iran’s military hardware and likely deployment strategy versus U.S. countermeasures Dr. Talmadge’s optimistic estimate for clearing the straits is 37 days. She allows 9 days to eliminate the anti-ship missile threat and another 28 days for U.S. ships to deal with the mines without having to worry about missiles raining down on them.  Her most pessimistic forecast is 112 days—72 days for the missiles and 40 days for disabling enough of Iran's naval mines.

Why are these numbers important? Because the world economy likely knows these figures too--or some number in the ballpark. If Iran can keep the Hormuz straits blocked for longer than a nominal 112 days, U.S. allies will begin to lose faith in her as the guarantor of the lifeblood of their economies, energy. This loss of confidence would threaten to unravel the U.S. global empire. The risk is tiny, but the price may be more than the U.S. can afford. So, any U.S. decision maker would hesitate to attack Iran, weighing the low risk against the high price.

One interesting deduction that Dr. Talmadge makes is that Iran likely does not have the Russian SA 300 (SA-10 Grumble) missile defense system. She bases this on the fact that one of Iran’s deterrence strategies is to boast about military hardware. Firing one or two SA 300s during a war exercise would cause the U.S. to reassess how long it would take to open up the Hormuz Straits, causing her to back off for a while. Yet Iran has not used anything like the SA 300 in its war games, even though this system can seriously hamper the ability of U.S. aircraft to take out Iran’s anti-ship missile batteries--while the clock ticks against the 112 days.

Dunno about Dr. Talmadge’s analysis of the SA 300 issue. For one thing, Russia’s claim that the ordered missiles have not been delivered to Iran is a matter of debate. Furthermore, Iran is said to have acquired the missiles from Belarus (who denies it), and Iran may have even developed a similar system on her own. The latter scenario seems unlikely to many experts, but on the other hand it seemed unlikely that Iran had the technology to capture a U.S. aerial drone. Yet Iran has done just that, or has made it appear so. Besides, not every piece of hardware can be displayed for the purpose of deterrence; some things have to be kept as surprises in case war breaks out.

In the conclusion to her analysis Dr. Talmadge seems worried:

“Iran’s limitations, such as the command and control and targeting challenges it would face in littoral [coastal]  warfare, are not often appreciated [to find out what these limitaions are, you can read the paper]. But its strengths are often overlooked as well…Likewise, although the United States retains the world’s best conventional military, its past experiences hunting mobile targets from the air and conducting MCM [mine countermeasures] operations in the littorals do not inspire confidence that confrontation in the strait would end quickly.. Given these realities, sanguine assurances about the course and outcome of military conflict in the strait seem unjustified at best, and dangerous at worst.”

Makes sense to me!



Totally unnecessary note: This writing is about just one aspect of the possible Iran-U.S. military confrontation, namely the closing of the Straits of Hormuz. 


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Veiled Prophet of Khorasan

Re: Compare and contrast

by Veiled Prophet of Khorasan on


  • Compare and contrast: Number of ships does not matter it is what they do. A single high tech submarine will sink a 100 ships with torpedoes. 
  • Regarding "The Gulf": please would posters refer to it by its name "Persian Gulf". It is bad enough that BBC insists on "The Gulf" we don't need to follow.
  • If IRI tries messing with oil shipments it is the perfect excuse to hit them. America may not need to attack them but might do so anyway.

There is no brinkmanship but plain stupidity in action. Khamenei is getting old an senile. Messing with the whole global economy and thinking he is powerful. He got a thing coming as did all those who overstepped their position.

Bahram G


by Bahram G on

In the event of war, would the US go about it half-heartedly? I mean in a very limited, potentially prolonged tit for tat? Or, go all guns blazing to finish of the mullahs?

Mobile launchers are hard to locate and destroyed, experts say. But wouldn't their operation require intimate connection with Command and Control? Wouldn't the US completely obliterate IRI c & e like they did to Saddam's? And the saudi's extensive and modern aircrafts will likely be itching to take to the Iranian skies and do their own hunting. And don't forget Israel. Who is going to come to the aid of the zany mullahs? The RISH o PASHM top brass? Do those guys themselves actually know how to fire anything but YA HUSSEIN. And we all know how good Hussein was when he was alive.

I hate this whole brinksmanship. Because it can push things to actual war. And the era of settling disputes through violence and war should be behind us, although the mullahs live by violence against defenseless people. Hey mullahs, the US and it's allies are not a group of grieving old women or a bunch of defenseless unarmed students that you can torment with impunity. Be careful. Be very careful, or you will get to meet imam Hussein before you can blink.


A paper from FP and Daniel Yergin's view

by Mehrban on


The paper above argues that the characteristics of the strait itself and the chracteristics of oil tankers make it virtually impossible for Iran to effectively close the strait.

Daniel Yergin the prime energy expert in his book "the Quest" mentions similar difficulties.  He also points out that in addition to retaliatory action from US Fifth fleet in Bahrain, the closing of the strait is no longer viewed as an assault on the West but the East as well.  He says that China gets a quarter of its oil from the Gulf, an open straight is where the interest of the US and China coincide and there would be  worldwide coalition against Iran. Yergin thinks that oil prices will initially spike but he does not view the possibility as "catastrophic" (Yergin's word).  

My interjection is that keeping the strait open does not require and does not mean an all out war with Iran, contrary to what some have been trying to argue.


Compare and contrast

by Hooshang Tarreh-Gol on


Total Navy Ships: 261
Merchant Marine Strength: 74 [2011]
Major Ports & Terminals: 3
Aircraft Carriers: 0 [2011]
Destroyers: 3 [2011]
Submarines: 19 [2011]
Frigates: 5 [2011]
Patrol Craft: 198 [2011]
Mine Warfare Craft: 7 [2011]
Amphibious Assault Craft: 26



 Total Navy Ships: 2,384
 Merchant Marine Strength: 418 [2011]
 Major Ports & Terminals: 21
 Aircraft Carriers: 11 [2011]
 Destroyers: 59 [2011]
 Submarines: 75 [2011]
 Frigates: 30 [2011]
 Patrol Craft: 12 [2011]
 Mine Warfare Craft: 14 [2011]
 Amphibious Assault Craft: 30


UK  Total Navy Ships: 99
 Merchant Marine Strength: 527 [2011]
 Major Ports & Terminals: 10
 Aircraft Carriers: 1 [2011]
 Destroyers: 6 [2011]
 Submarines: 11 [2011]
 Frigates: 13 [2011]
 Patrol Craft: 23 [2011]
 Mine Warfare Craft: 15 [2011]
 Amphibious Assault Craft: 10



 Total Navy Ships: 289
 Merchant Marine Strength: 167 [2011]
 Major Ports & Terminals: 7
 Aircraft Carriers: 1 [2011]
 Destroyers: 0 [2011]
 Submarines: 10 [2011]
 Frigates: 23 [2011]
 Patrol Craft: 35 [2011]
 Mine Warfare Craft: 18 [2011]
 Amphibious Assault Craft: 13


Veiled Prophet of Khorasan

This is bull

by Veiled Prophet of Khorasan on


With all due respect to MIT and Ari both of whom I respect. This analysis is totally wrong. It leaves out many options an pretends it is USA acting with its hands tied. That will not be the situation. As others said:

  • The analysis does not take into account non USA militaries.
  • It forgets the damage IRI will suffer due to lack of funds and refined gas.
  • It leaves out the fact that Iranian opposition internally. They may use it to  turn up protests. Which might just get USA air support.
  • It forgets retaliation in form of a naval blockade.
  • It is heavily biased towards IRI. Basically assumes USA would back off; while they might go the other way. Intensify and intensify its attacks rather than move back.
  • It forgets Iran is surrounded. Meaning a response need not be limited to a Naval one. For example USA might just decide to level Qum.


Besides this will give America both internal and world support. They get to hit IRI any way they want and no one will mind. From total economic isolation to a full fledged occupation of southern mainly the Persian Gulf regions of Iran.

This is an election year and Obama is not going to "be weak". He may well decide to let them have it. Yes the missile launchers may be mobile. But Qum and many IRI military and power centers are not. Maybe USA will hit them instead.



Iran flexing muscles like a peacock...

by hirre on

I work with military R&D and analysis and I can say ~1-2 months is very optimistic in favor of Iran. It would take 1-2 months if the world doesn't do anything for weeks, starting from the time of when the closing begins. But if the world is prepared for the closing, it would only take days to 1-2 weeks. Iran simply doesn't have the military capability to launch a successful project like that. Right now Iran has ~8 ships, 5 frigates, 3 corvettes.

In order to block an international transport route, you would need operational cruisers, destroyers and carriers which Iran doesn't have, Iran does not have any capital ships (// Iran has many small and light patrol boats (similar to what is used by the non-military police in the west in order to maintain law on the sea), but not enough "heavy steel".  Just compare Iran's naval capability with the US navy (although all ships aren't present in the Persian Gulf):



Also don't forget that this is only the US navy, there are other western military naval ships present in the Persian Gulf which will attack iranian vessels if Iran is going to block the route. The only thing Iran can to is to do what the nazis did with their submarines (although in a much restricted version). They could perform scare tactics and perhaps sink 1-2 ships, but nothing critical to the whole operation...

The only reason there is any hesitation is because of politics, how will china & russia respond (if they respond) & what impact will it have on current US domestic politics and the relationship to Europe?...


Revolutionary Guards are purse snatchers

by ilovechelokebab on

Revolutionary Guards can't do jack shit! What can they do with their out of date equipment? Also they are not a professional military organization, they resemble an organized crime syndicate rather than a military organization. Remember, professional soldiers do not harm civilians! The so called Guards do! Remember the fucking riots a few summers ago when the regime ALMOST collapsed but in absence of outside moral support for the protesters and the fucking bastards Mousavi and Karoubi who fooled the proteters! Millions were in the streets but the protesters were betrayed! BETRAYED! 


A hundred-and-twelver dream........

by پندارنیک on

Wouldn't be sweet to see the American President on the CNN drinking the cup of poison?

A good blog, very good........I hope my comment is the first and the last spoiler, only to be followed by some expert remarks..............


Can Islamic Republic last 112 days without Oil income?

by Hooshang Tarreh-Gol on

Probably not. Total Reserves of Foreign Exchange & Gold for 2011 was, $75,060,000,000. This was the figure before all the latest currency instabilities.     I'm more of an arm chair 'analyst' than you, so in that spirit;   Wouldn't any interruption in there also damage IR's allies, mainly China?   The other navies no one mentions that are also there in Persian Gulf and Sea of Oman are English and French Navies.   IR might have developed its own surface to air missile system, but would that be a match for a combined US, Brits, French attack?