[custom_adv] Revolutionary Guard patrol boats shadow the USS John C. Stennis aircraft carrier on Friday, Dec. 21, 2018. The U.S. [custom_adv] aircraft carrier sailed into the Persian Gulf on Friday, becoming the first since America's withdrawal from the nuclear deal and breaking the longest carrier absence in the volatile region since at least the Sept. 11 terror attacks. (AP Photo/Jon Gambrell) [custom_adv] A U.S. aircraft carrier has sailed into the Persian Gulf, becoming the first in the region since President Donald Trump's decision to withdraw from the nuclear deal earlier this year. [custom_adv] The December 21 arrival of the USS John C. Stennis came amid repeated threats by officials to close off the Strait of Hormuz, the narrow mouth of the gulf and the only outlet through which all ship traffic passes. [custom_adv] Iranian Revolutionary Guard vessels followed the carrier and its strike group as it arrived. There were also sightings of a drone, as well as rockets being test-fired away from the U.S. ships. [custom_adv] Iranian sailors on the accompanying ships could be seen photographing and videotaping the U.S. ships. [custom_adv] “There are a lot of us who want to avoid a shutdown,” said Kansas GOP Sen. Pat Roberts. “I’ve been through about five of them in my career. None of them have worked in terms of their intent.” [custom_adv] Tensions with have been high since Trump's announcement that the United States was pulling out of the 2015 nuclear deal, which lifted crippling sanctions in exchange for curtailing its nuclear activities. [custom_adv] a major exporter of oil and a member of the OPEC oil cartel. President Hassan Rohani has repeatedly warned any attempt to stop Iran's exports could cause it to close off the strait. [custom_adv] A U.S. aircraft carrier sailed into the Persian Gulf on Friday, becoming the first since America’s withdrawal from the nuclear deal in May and breaking the longest carrier absence in the volatile region since at least the Sept. [custom_adv] The arrival of the USS John C. Stennis comes as Iranian officials have returned to repeatedly threatening to close off the Strait of Hormuz, the narrow mouth of the Persian Gulf through which a third of all oil traded by sea passes. [custom_adv] Revolutionary Guard vessels shadowed the Stennis and its strike group, at one point launching rockets away from it and flying a drone nearby. [custom_adv] The long absence of a carrier, however, could become a standard practice here as now-outgoing Defense Secretary Jim Mattis sought to shake up naval operations and American air bases spanning the region can scramble fighter jets and drones. [custom_adv] The U.S. military also operates air bases in Qatar and the United Arab Emirates, as well as a major Army base in Kuwait and its Navy base in Bahrain. That offers the American military a variety of locations both in the Persian Gulf, as well as other bases in the wider Mideast, to launch strikes. [custom_adv] It's unclear, however, whether Mattis' strategy will continue. The defense secretary resigned Thursday after clashing with Trump over the abrupt withdrawal of U.S. troops from Syria.