BEIRUT, Lebanon -- Iran's Islamic Revolutionary Guards Corps said it had deployed its newly acquired Russian-made long-range S-300 air-defense system around one of the country's most strategic nuclear facilities, the underground uranium enrichment center near the holy city of Qom, amid a string of military moves intended to provoke the United States.
Iran's state media reported on Aug. 29 that the Russian-built S-300, capable of tracking multiple aircraft and missiles simultaneously, had been installed around the Fordow facility, which is deep inside a mountain about 62 milessouth of Tehran.
Another S-300 unit was deployed in May at the IRGC's Khatam al-Anbia Air Defense Base in the northern province of Semnan, believed to be a key air-defense nerve center.
Iran is deeply concerned about the possibility of Israeli air- or missile strikes at its nuclear facilities and, to a lesser extent, about U.S. attacks.
Growing tensions with Saudi Arabia, Iran's longtime regional rival, and possible strikes by the kingdom's U.S.-built jets have probably sharpened Tehran's concerns.
The S-300 deployment at Fordow illustrates the importance the Iranians place on the facility in their nuclear program, which has been curtailed under the July 2015 agreement in exchange for lifting crippling economic sanctions on Iran.
That deal took effect in January and Fordow has not been operating since then. Whether the deployment indicates the Iranians may plan to restart uranium enrichment, the core of the nuclear weapons program, is not known.
As it is, the positioning of the S-300s is certain to raise U.S. concerns triggered in large part by continued anti-U.S. pronouncements from hardliners in Tehran who tolerated reformist President Hassan Rohani's diplomatic outreach only because the supreme leader, Ayatollah Ali Khamenei, decreed they must.
There is considerable residual opposition in Iran to any form of rapprochement with the United States and tensions have risen in recent months over a series of Iranian ballistic missile tests, which the United States considers a violation of U.N. Security Council resolutions and a breach of the landmark 2015 agreement between Iran and U.S.-led global powers.
On Aug. 17, the director of the U.S. Missile Defense Agency, U.S. Navy Vice Adm. James Syring, cautioned that Iran and North Korea, which has a long history of collaborating with the Islamic republic, have stepped up their programs to develop long-range ballistic missiles.
Iran has continued to test "in numbers and increase of capability," developing its Shahab-3 intermediate-range ballistic missile, Syring told the Space and Missile Defense Symposium in Huntsville, Ala.
At the same time, the IRGC, which controls Iran's missile program and its growing arsenal of operational weapons, has improved the precision and accuracy of the Emad ballistic missile, Syring said.
North Korea has contributed greatly to the development of Iran's ballistic weapons and the six recent tests of its Musudan IRBM, which has a range of about 1,200 miles, and its breakthrough launch of a ballistic weapon from a submarine in April may well accelerate similar efforts by the Islamic Republic.
U.S. concerns have mounted amid a recent wave of arrests of dual-national citizens on allegations of treason and espionage, possibly as pushback against the 2015 deal.
Khamenei heightened tensions by declaring, in apparent reference to the United States, that "the enemy should understand that if it makes any aggression, it will be hit hard and our defenses will also include response."
Khamenei's remarks, made during an Aug. 28 speech at an airbase near Tehran, came four days after n a series of incidents in which Iranian warships harassed U.S. Navy vessels in the Arabian Gulf and the Strait of Hormuz, the only way in and out of the waterway and a vital oil tanker route. It happened again Sunday.
He declared that Iran's military power was for defensive purposes. He insisted the S-300 "is a defense system not an assault one but the Americans did their utmost to prevent Iran from getting it."
However, the S-300, due to its long range, can be used for offensive operations because it is able to shoot down aircraft far beyond Iran's airspace and could thus target U.S. aircraft in the Gulf region, along with aircraft from Saudi Arabia and the United Arab Emirates, the major military powers on the western, Arab shore of the Gulf, almost as soon as they were to take off from their bases.
In June, the IRGC's deputy commander, Gen. Hossein Salami, warned that Iranian forces would close the Strait of Hormuz if the United States "threatened" Iran.
Tehran has made similar threats many times over the past 20 years and despite naval confrontations has made no serious attempt to close the narrow strait.
But that was when the United States deployed its 5th Fleet in the region, usually including at least one aircraft carrier battle group and sometimes two. But now U.S. forces are being scaled down under hefty cuts in military spending amid a pivot to the Pacific to counter China.
U.S. defense consultant Peter Huessy, president of Washington-based GeoStrategic Analysis, observed in the journal Defense News: "Unfortunately, the U.S. Navy's ability to keep the strait open is weaker than in the recent past and Iranian military capabilities are measurably stronger."
The difficulties in keeping the narrow waterway open if Iran sought to close it were demonstrated in a 2002 Pentagon war game, Millennium Challenge, that tested U.S. capabilities.
The result was a spectacular failure. "A carrier and 10 cruisers were sunk" by the Red Team, representing Iran, which was headed by a retired U.S. Marine general.
Since then, Huessy cautioned, "The U.S. fleet's weapons, tactics and strategy have only been marginally improved. The fleet has shrunk to 272 combatant ships even in the face of analysis that a robust maritime security strategy can only be implemented with a fleet of at least 350 ships...
"Just 5 of our 10 carrier battle groups are now operational and only two are regularly available."
The Navy Times recently reported that the "tense waters of the Asia-Pacific or the Middle East could go for weeks or months without a U.S. carrier patrolling there."
This article originally appeared at The Arab Weekly.