As U.S. warships helped Israel shoot down missiles from an Iranian attack on Tuesday, the Pentagon was preparing to send thousands more U.S. troops, including three additional aircraft squadrons, to the Middle East.
That highlighted the scale of the American military presence in a region where war appears to be spreading.
Here’s an overview of where U.S. forces are operating in the Middle East, and what they are doing:
Eastern Mediterranean
The United States has an amphibious assault ship and three guided-missile destroyers in the eastern Mediterranean, the part of the sea that borders Israel and Lebanon.
U.S. warships there helped Israel shoot down Iranian missiles on Tuesday, President Biden told reporters after the attack.
An aircraft carrier, the Harry S. Truman, left Virginia in late September on a scheduled deployment to the eastern Mediterranean. As of Monday it was still crossing the Atlantic.
Red Sea
In the Red Sea, which lies south of Israel and borders Yemen and other countries, U.S. forces have been trying in recent months to stop attacks on commercial ships by the Houthis, an Iranian-backed militia that has described itself as acting in solidarity with Hamas. Some American ships have come under attack.
As of Monday, the Navy had deployed several guided missile destroyers to the sea, according to the U.S. Naval Institute.
Gulf of Oman
The aircraft carrier Abraham Lincoln is on an extended deployment in the Gulf of Oman, south of Iran. Like other aircraft carriers, it is part of what is known as a carrier strike group, which also includes fighter jets and guided-missile destroyers.
In August, Defense Secretary Lloyd J. Austin III sent the Abraham Lincoln’s strike group to the Middle East as part of an effort to strengthen the U.S. presence in the region. On Sunday, he ordered it to remain there.
Military bases
About 40,000 American troops are stationed on bases across the Middle East. On Tuesday, the Pentagon declined to say how many more it was deploying, saying only that it would send a “few thousand.”
As of September, about 2,500 troops were in Iraq, many of whom served as a defense against attacks by a resurgent Islamic State, and 900 in neighboring Syria.
Qatar, across the Persian Gulf from Iran, hosts the largest U.S. military base in the Middle East. Nearby Bahrain and the United Arab Emirates also host American bases, as does Djibouti, an African country across the Red Sea from Yemen.
Kuwait, southeast of Iraq on the Persian Gulf, had about 13,500 U.S. troops on bases as of 2021. At the time, only Germany, Japan and South Korea had more U.S. forces. Kuwait was a hub for American forces during the Iraq war.