Terrorism

Afghanistan

Troops: About 1,000 soldiers from the 101st Airborne Division, soldiers from the 10th Mountain Division and various Special Forces units.

Location: Kandahar International Airport, Bagram Air Base and Mazar-i Sharif. Special Forces units operate across the country.

Equipment: The U.S. also has two carrier battle groups in the Arabian Sea. The carriers are the USS John C. Stennis and USS Theodore Roosevelt. B-1 and B-52 bombers also are still available at the joint U.S.-British air base on the Indian Ocean island of Diego Garcia.

Pakistan

Pakistan has allowed the use of three airfields by the coalition forces operating inside Afghanistan. Dalbandin Air Base in western Pakistan has played a role in coalition operations along with airfields in Jacobabad, about 150 miles from the Afghan border in south-central Pakistan, and Pasni, a coastal military base along the Arabian Sea, about 125 miles from the Iranian border.

Kyrgyzstan

Troops: Nearly 1,000 U.S. Air Force personnel

Location: Air base near the capital of Bishkek

Equipment: The base eventually will be home to cargo, refueling and transport aircraft and some fighter jets.

Uzbekistan

Troops: Roughly 1,000 soldiers from the 10th Mountain Division.

Location: Khanabad Air Base

Equipment: A variety of aircraft, possibly including attack helicopters

Georgia

Troops: Between 45 and 200 U.S. Army and Air Force special operations forces are under consideration, according to Pentagon sources

Location: Near the capital of Tiblisi

Equipment: 10 unarmed UH-1 Huey helicopters were sent last October along with a team consisting of one U.S. service member and seven contractors to help with maintenance.

Yemen

The United States is prepared to send a small contingent of troops into Yemen to assist that nation's effort to root out al Qaeda and other terrorist cells, a senior U.S. official told CNN. The emphasis of the still-evolving operation would be to train Yemeni forces and share intelligence, the official said.

Philippines

Troops: 660 U.S. soldiers are aiding the Philippine army, including groups of 12 Special Forces soldiers attached to 10 Philippine army battalions.

Location: Island of Basilan

Equipment: Assorted aircraft

Army Rangers

As with all special operations forces, the U.S. Army Rangers report to the Joint Special Operations Command (JSOC) when in hostile or war situations. Along with the Rangers, which consists of one active regiment with three battalions, the U.S. Army Special Operations Command includes Army National Guard, civil affairs, psychological operations and chemical reconnaissance groups.

But the Rangers, themselves, are the spearhead of the Army's special operations forces. Ready to deploy by land, air and sea anywhere in the world at a moment's notice, Rangers specialize in rapid infantry assault, night fighting and airfield seizure. The Rangers are trained to infiltrate and exit by air, land or sea and have the capability to conduct conventional or special light-infantry operations.

According to the JSOC, the Rangers have taken part in every major combat operation since the end of the Vietnam War. In many cases, they are supported by the 160th Special Operations Aviations Regiment -- better known as the "Night Stalkers" -- which use state-of-the-art aircraft and equipment to assist all special operations forces from the air.

The Green Berets are used both as a combat force and to train guerrilla troops in other countries. Each member must be able to speak at least one language other than English.

The Green Berets are used for a variety of missions such as unconventional warfare, special reconnaissance, direct action and counter terrorism.

The Special Forces (Airborne) served in Vietnam, Operation Just Cause (in Panama) and Operations Desert Shield and Desert Storm.

While not technically a "special operations force," the Marines describe their expeditionary units as "special operations capable." These units -- at least two of which are in the Indian Ocean -- are capable of quick, compact, multi-faceted military campaigns.

These units generally have more equipment, logistical and technical support, weaponry and marines than their conventional counterparts, giving them more firepower. Their purpose is to provide the commander-in-chief an operational maneuver capability from the sea.

Commanded by a colonel, one Marine expeditionary unit typically includes about 2,200 personnel. The infantry battalion uses amphibious assault and light-armored vehicles, and the aviation unit employs helicopters and fixed-wing aircraft such as "Harrier" jets.

SEALs, which stand for Sea, Air, Land, are the U.S. Navy's primary and most acclaimed special operations forces unit. Operating mainly in tight 16-man groups, SEALs are capable of conducting top-secret ground and water-based missions.

SEALs are trained extensively and rigorously in and around San Diego, California, and Norfolk, Virginia, to withstand and, in fact, thrive in the face of personal, physical, environmental and other challenges. They trace their history to the frogmen of World War II, although new threats -- including terrorism -- have forced them to evolve substantially in recent years.

SEALs take on missions, many of them classified, throughout the world. Larger teams are often divided into "cells" -- i.e. an evasion and recovery cell, force protection cell, sniper cell, etc.

While the military acknowledges the existence of Special Mission Units, or SMUs, such as Delta Force, it does not specify what they are called or their specific locations, staffing or organizational structure. Unofficially, Delta Force