The decision comes one day after US Air Force B-52 bombers flew nonstop from the United States to the Persian Gulf in a show of force that military officials say was intended to caution Iran.
The Pentagon has decided to send home the only Navy aircraft carrier operating in the Middle East, a move that will reduce American firepower in the region amid heightened tensions with Iran.
The decision, announced on Thursday by Acting Secretary of Defense Christopher Miller, came one day after US Air Force B-52 bombers flew nonstop from the United States to the Persian Gulf in a show of force that military officials said was intended to caution Iran against carrying out attacks against US forces or interests.
Sending the aircraft carrier, the USS Nimitz, home to the US West Coast would seem at odds with the idea that a show of force is needed to deter Iran.
This might reflect a split within the defence establishment on whether Iran poses a heightened threat to strike in the waning days of the Trump administration. In announcing the decision to send the Nimitz home, Miller made no mention of Iran.
Earlier this week, an American military officer close to the situation told reporters that the US had detected signs that Iran had made preparations for possible attacks on US or allied targets in Iraq or elsewhere in the Mideast.
This was the reason for dispatching two B-52 bombers from the US to briefly overfly the Gulf on Wednesday, said the officer, who spoke on condition of anonymity to discuss internal assessments.
President Donald Trump recently cited “chatter” that Iran might strike. Days after a December 20 rocket attack on the US Embassy compound in Baghdad by Iranian-supported Shia militia groups, Trump tweeted that Iran was on notice.
“Some friendly health advice to Iran: If one American is killed, I will hold Iran responsible. Think it over,” Trump wrote on December 23. He added, ”We hear chatter of additional attacks against Americans in Iraq.”
Killing of Soleimani
US concerns have been tied to the approach of the January 3 anniversary of the American air strike that killed Iran's top commander, General Qassem Soleimani.
Iran initially retaliated with a ballistic missile strike on a military base in neighbouring Iraq that caused dozens of brain concussion injuries but no deaths among US troops. But US officials are concerned that Iran might be planning further retaliation.
Because of the potential for escalation that could lead to a wider war, the US has sought to deter Iran from additional attacks. Strategic calculations on both sides are further complicated by the political transition in Washington to a Biden administration that may seek new paths to dealing with Iran.
President-elect Joe Biden has said that he hopes to return the US to a 2015 agreement with world powers in which Iran agreed to limit its nuclear activities in exchange for the lifting of international sanctions.
Aircraft carrier presence
The US has maintained a near-continuous aircraft carrier presence in the Persian Gulf region since the USS Abraham Lincoln was sent in May 2019 amid concerns that Iran was considering attacking US interests in the region.
The US also sent additional land-based attack planes and reestablished a troop presence in Saudi Arabia.
The Nimitz deployed from the US in April and was due to return before the end of the year. In early December, its planned return was postponed, in part out of concerns about potential Iranian threats, and more recently it was ordered to provide support off the coast of Somalia for the movement of American forces out of the country.