New US-led patrols in Persian Gulf raise stakes with Iran

As the U.S. tries a new way to protect shipping across the Persian Gulf amid tensions with Iran, it finds itself sailing into uncertain waters.

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."