Dubai: For decades, the U.S. has considered the waters of the Persian Gulf as critical to its national security.
Through the gulf's narrow mouth, the Strait of Hormuz, 20% of all crude oil sold passes onto the world market. Any disruption there likely will see energy prices spike.
The U.S. has been willing to use its firepower to ensure that doesn't happen. It escorted ships here in the so-called 1980s "Tanker War."
America fought its last major naval battle in these waters in 1988 against Iran.
Now, the U.S. Navy is trying to put together a new coalition of nations to counter what it sees as a renewed maritime threat from Iran.
But the situation decades later couldn't be more different. The U.S. public is fatigued from years of Mideast warfare after the Sept. 11 attacks.
The demand for Persian Gulf oil has switched to Asia. Gulf Arab nations poured billions of dollars into their own weapons purchases while inviting a host of nations to station their own forces here, even as infighting dominates their relations.
Meanwhile, Iran finds itself backed into a corner and ready for a possible conflict it had 30 years for which to prepare.
It stands poised this week to further break the terms of its 2015 nuclear deal with world powers, over a year after President Donald Trump unilaterally withdrew America from the accord and imposed crippling sanctions on the country.
"It is plausible to imagine a scenario where these forces stumble into some type of accidental escalation," said Becca Wasser, a senior policy analyst at the RAND Corp. who studies the region.
"While U.S. efforts are intended to deter, Iran may view increased U.S. maritime presence as offensive in nature or as preparation for a larger attack on Iran and respond accordingly."
The U.S.-led Sentinel Program aims to secure the broader Persian Gulf region. It includes surveillance of the Strait of Hormuz and the Bab el-Mandeb, another narrow strait that connects the Red Sea and the Gulf of Aden off Yemen and East Africa.
Smaller patrol boats and other craft will be available for rapid response. The plan also allows for nations to escort their own ships through the region, said Cmdr. Joshua Frey, a spokesman for the U.S. Navy's 5th Fleet, which oversees the region.
For now, the Bahrain-based 5th Fleet is not escorting U.S.-flagged ships through waters, though that remains a possibility, he said.
So far, only Australia, Bahrain and the United Kingdom have said they'll join the U.S. program.
India has begun escorting its own ships independently of the U.S. coalition, while China has suggested it could get involved as well.
The U.S. Navy has sent Arleigh Burke-class guided-missile destroyers to chokepoint positions, like either end of the Strait of Hormuz.
There, they observe-ship traffic and monitor for anything unusual as drones and other aircraft fly surveillance routes overhead, Frey said.
Some of what the U.S. plan calls for already falls under the routine operations of the 5th Fleet, which has been in the region since 1995. U.S. Navy ships coming in and out of the Persian Gulf often find themselves shadowed by Iranian Revolutionary Guard vessels.
Some incidents have seen the U.S. fire warning shots or Iranian forces test-fire missiles nearby. What's different now though is shippers find themselves under attack.
The U.S. blames Iran for the apparent limpet mine explosions on four vessels in May and another two in June sailing in the Gulf of Oman near the Strait of Hormuz, something Iran denies being behind. Iran also seized a British-flagged oil tanker and another based in the United Arab Emirates.
Facing growing financial pressure from U.S. sanctions on its oil industry, Iran has sought diplomatic support from those still in the deal, while increasing pressure militarily as well.
Even President Hassan Rouhani, who had supported rapprochement with the U.S. in the run-up to the 2015 deal, has been threatening to close off the Strait of Hormuz if Tehran can't sell its oil abroad.
"If someday, the United States decides to block Iran's oil, no oil will be exported from the Persian Gulf," he told a cheering crowd in December 2018. That raises the stakes for conflict.
"The United States is not seeking a military confrontation, and are certainly not soliciting international support for any provocation," Frey said.
"With that said, while the intent of our presence is deterrence and stability, we are prepared to defend (coalition) member nations' interests from attacks in the maritime domain."
But it won't be just the United States involved if things spin out of control, nor will it likely be confined to the high seas. Since the 1980 Carter Doctrine, the U.S. has vowed to use its military power to defend its interests in the oil-rich Persian Gulf.
That saw America enter the "Tanker War" toward the end of the 1980s Iran-Iraq war, in which U.S. naval ships escorted reflagged Kuwaiti oil tankers.
It culminated in a one-day naval battle between Washington and Tehran, and also saw America accidentally shoot down an Iranian passenger jet, killing 290 people.
The 1991 Gulf War, in which a U.S.-led coalition expelled Iraqi dictator Saddam Hussein's troops from Kuwait, further cemented America's presence, as did its later wars in Afghanistan and Iraq.
