The Navy announced in July that because of a tight budget it would not be able to send a new carrier out immediately to replace the Roosevelt. The next carrier, USS Harry S Truman, is expected to arrive in the region in mid-December, leaving a gap for two months.
This is the first time in eight years that the US Navy has left a gap in its carrier deployments in the region. Normally, carriers spent six months on duty in the Indian Ocean and Persian Gulf.
The Russians have sent 30 planes to an air base in Syria to bomb rebels fighting the government of Syrian President Bashar al-Assad.
Before the Roosevelt left, there were about 300 US aircraft in the region attacking the Taliban in Afghanistan and the Islamic State in Iraq and Syria. The departure of the Roosevelt removes 65 of those aircraft. The remaining aircraft fly from bases at Incirlik in Turkey, Al-Udeid in Qatar, Ali As-Salem in Kuwait, Shaikh Isa in Bahrain and Herir near Erbil in Iraqi Kurdistan.