The U.S. can not attack Iran because the attack and any Iranian retaliation would increase the price of oil to new record levels. Even if Iran were not to react to any attack the expectation of a possible reaction would be enough to explode the insurance premiums for any ship entering the Strait of Hormuz. With record oil prices over more than a few weeks all major economies would experience serious damage. Poorer economies would experience high price increases for staple food with social upheavals, like the Arab spring, certain to follow.
The Iran hawks argue against this. They say that U.S. navy is capable of keeping the Strait of Hormuz open even if Iran intends to close it. Even if the Strait were temporarily closed the U.S. navy would be able to reopen it immediately. They are wrong:
A major international naval exercise last month in and around the Persian Gulf and Arabian Sea, led by the U.S. Navy with more than 30 other nations participating, located fewer than half of the practice mines laid at sea.
This outcome of the highly publicized military drills — not publicly known until now — underscores how difficult it may be for the United States and its partners to detect and incapacitate waterborne explosive devices that Iran has threatened to plant if its nuclear facilities come under attack.
Out of the 29 simulated mines that were dropped in the water, “I don’t think a great many were found,” retired Navy Capt. Robert O’Donnell, a former mine warfare director for his service, told the NewsHour. “It was probably around half or less.”
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“I just felt that they should have done better,” said O’Donnell, clearly disappointed with the outcome of this key measure of performance. “That’s the point of the exercise, to do mine-countermine [operations] in an area, and to find the mines.”Now a consultant, O’Donnell was invited by the Navy to observe the September exercise firsthand as it unfolded.
The maneuver was disaster. But for people knowledgeable in the field it was also unsurprising. The U.S. Navy is traditionally incapable of serious mine clearing efforts. Even official documents (pdf) acknowledge this. The proposed solution to this disability is a combined effort by various navies under U.S. command:
The threat of mines presents a Unified Commander-in-Chief (CINC) with problems affecting the time-space-force aspects of his command. Further complicating this matter, is the U.S. Navy's inability to adequately address the mine threat problem unilaterally. History demonstrates that the U.S. Navy's inability to maintain a mine countermeasures (MCM) force sufficiently large enough and technologically advanced enough has been nominally off-set by the strengths of a combined MCM force.
The recent maneuver was a "combined" effort. Over 30 nations took part and even then only half of the dropped mines were found.
This was only a maneuver. A scripted training event without any threat from real mines or from other forces. Under the threat of fire from Iran's Silkworm derived anti-ship missiles fired from this or that cave or truck on the Iranian coast plus under the threat of real mines the clearing percentage would likely be worse.
What conclusion will those ship insurers in London draw from this? Right.
The U.S. navy has for some time tried to develop new mine hunting systems to be put on the new class of oversized unarmed speedboats Littoral Combat Ships. These efforts have so far failed. When they eventually succeed the capability of the new system will likely be much less than expected.
Unless there is technological leap in mine hunting and clearing coming up (unlikely), the threat and the capability of mining the Straits is likely enough to keep Iran safe from serious military aggressions.