Elite Unit Operates Behind Enemy Lines : Special force: SAS troops are credited with helping capture 400 Iraqis.

The crack troopers of the top-secret British Special Air Service Regiment (SAS) are operating behind the lines in Kuwait and Iraq and are expected to play a key role in relaying information to the main allied armies in the Gulf ground war, according to senior military sources here.

SAS teams, the sources say, have been been placed in Iraq and Kuwait to monitor Iraqi army activities, and to send, via sophisticated communications equipment, valued intelligence to allied headquarters in Riyadh. They are also equipped to direct air and artillery strikes against Iraqi military formations.

About 150 members of the elite SAS Regiment are said to be in the Gulf theater and probably played a role in effecting the surrender of more than 400 Iraqi soldiers last week, military sources here said.

SAS operations have always been classified, and British Defense Ministry officials will make no public mention of their presence in the Persian Gulf--or anywhere else.

But the teams “are most probably being used to follow enemy troop movements and direct air and artillery fire on significant targets,” said retired Gen. Ken Perkins, who has worked closely with the SAS in desert operations.

The SAS long has been considered among the best trained, most accomplished military special forces in the world. The U.S. Delta Force was modeled on the SAS concept. The SAS in recent years has received more attention for its expertise in developing anti-terrorist capabilities and techniques; its members are trained to assault hijacked airliners or buildings taken over by terrorists.

Many observers remember seeing live television pictures showing the SAS assault on the Iranian Embassy in London in May, 1980, when the black-uniformed, gas-masked, machine-gun toting troopers rappelled into the building and killed or wounded the terrorists in minutes.

While known for its anti-terrorist work, the SAS also has maintained its long-range, military role. Its present role in the Gulf War brings it full circle.

The SAS was created in 1940 as the Long Range Desert Group, and during World War II, its members served as a sweeping reconnaissance force in the trackless terrain of Egypt and Libya. It was transformed into a special unit by Lt. David Stirling, who later would become a colonel and who called the outfit the Special Air Service because of its paratrooper capability.

Operating out of Egypt, the SAS moved behind enemy lines, seeking to blow up German and Italian enemy bases and to capture senior enemy officers. It later conducted the same long-range, secret missions in the Greek islands and the Balkans.

The SAS--whose emblem is a winged dagger and whose motto is “Who Dares Wins”--developed its own special weapons and easygoing but stern discipline. The regiment developed a reputation for independent action by small groups of very highly trained men, operating deep behind enemy lines.

The SAS was disbanded after the war. But during the postwar anti-colonial period, it was reinstated.