In the late 1970s, as the worldwide oil crisis heated up, an Arlington, Va., company headed by a former Central Intelligence Agency staffer came here to the remote Musandam Peninsula.

Iran lies just 26 miles away, across the strategic Strait of Hormuz, through which much of the world's oil supply is carried by a steady parade of tankers out of the Persian Gulf.

The stated business of Tetra Tech International Inc. is development. But the power it came to wield here is, in the words of one employe, "a little peculiar."

On contract with the government of Oman, TTI helped set up the Musandam Development Committee in 1976. In that capacity, it was given supervisory control in 1979 over the operations of 11 government ministries.

TTI's employes have supervised activities from road building and port construction to minor details of everyday life. They inspect the few restaurants here for hygiene. They tie up goats found wandering the streets and fine their owners.

Oman's Sultan Qaboos, often described as the United States' closest friend on the Persian Gulf and a man who has relied heavily on foreign advisers and employes in every aspect of his country's development, needed to secure the Musandam quickly and efficiently in 1979.

The strictly military aspects of that job were given to the Omani Army, much of which is commanded by British officers. At the same time, the United States began investing hundreds of millions of dollars in upgrading four Omani air bases to handle fighter and transport planes if Washington should be called on to defend the gulf. One is the Khasab field, where the U.S. Army Corps of Engineers replaced the old 2,000-foot dirt strip with a 6,500-foot runway.

Most of the rest of the work done here was carried out under TTI, whose president, James H. Critchfield, served the CIA as Middle East desk officer and a national intelligence officer for energy until 1974, according to several published reports, including one in The New York Times last March 26, and confirmed by Critchfield, reached by telephone in Arlington last week.

In the Musandam there were special problems to which a man with such a background might be sensitive. As one British consultant to the sultan put it, Qaboos had to keep the remote peninsula from "floating away" politically.

The Musandam, with a population of about 11,500, is separated from the rest of Oman by about 40 miles of territory of the United Arab Emirates.

Many fishermen on the coast still use the boom, a traditional wooden boat, to bring in their catches. The Bedouins among the crags of the mountains carry walking sticks topped with small stone axheads.

For generations tribal rivalries and feuds wracked the peninsula. Some villages until recently professed loyalty to the sheiks of the United Arab Emirates rather than to the sultan of Oman.

In Khasab, the biggest settlement, about 40 percent of the population is Iranian or of Iranian descent. Little Iranian fishing launches still move in and out of the Khasab port.

"With twin engines on the back you can bang across to Iran in an hour and a half," said a foreign worker here. Iran seems a closer neighbor than the rest of Oman.

TTI's projects are a highly sophisticated example of what soldiers like to call civic action, aimed at winning and holding the sometimes shaky allegiances of the peninsula's people. In an area such as this, development can be seen essentially as preventive medicine against subversion.

Sultan Qaboos, a graduate of Britain's Sandhurst military academy, is expert in the nuances of such undertakings.

After taking power from his father, with British encouragement, in 1970, Qaboos spent the first five years of his reign crushing a Communist-backed rebellion in the southern province of Dhofar. He was aided by British forces, including the Special Air Service and intelligence officers who put a premium on civic action.

"The Dhofar war was eventually successful," said a senior British officer in Oman's capital, Muscat, "because civil projects followed very quickly on military success."

But while Dhofar and Muscat began to prosper, the Musandam stood still.

There were no telephones and virtually no roads. Most of the Musandam's people could be reached only by sea, by helicopter, by donkey or on foot.

In such circumstances, "you have to make doubly sure the population is well cared for," said the British officer in Muscat.

"Whether you call it psychological warfare, 'hearts and minds' or whatever," he said, "it's common sense." But he added that he could not comment on details.

"It's very much a U.S.-led operation," he said.

According to its employes here, Tetra Tech International was originally part of Tetra Tech, a Pasadena, Calif., company that deals with water and energy resources as well as underwater weapons development.

But after Honeywell Inc. acquired the parent company, TTI broke off, its employes here said. Critchfield remains in charge at the home office in Arlington.

In 1979 and 1980, TTI, acting through the development committee, took over "the work and power" of several ministries here, including agriculture and fisheries, power, water, the post office and telecommunications, information, land affairs, municipalities, youth affairs and public works, according to an offical committee fact sheet.

One of the few ministries over which TTI does not have jurisdiction here is defense. But military activities affecting the local population are closely coordinated with the development committee.

In addition to a sophisticated listening post and military base on Goat Island just west of the Musandam's tip, the Omani military recently created a new secret installation at the village of Qabal, on the east coast, according to residents here. These sources said it was TTI's job to relocate the residents of the town the Army took over.

John Dymond, a TTI employe, is director of operations for the Musandam Development Committee. He was formerly an engineer in the British Navy and then on the sultan's royal yacht, and came here in 1980.

He denies any direct intelligence function, but he readily acknowledges that many of his projects have basic military value.

A computerized census he did, for instance, "basically listed every house, every man" in the peninsula. The roads built under his supervision are punctuated by helicopter pads. But the primary motive for such undertakings is to be able to deliver services better, Dymond said.

One of the development committee's main activities is to distribute water in this arid land. It has its own desalinization plants and is responsible for filling hundreds of water tanks throughout the region. It also keeps cisterns in repair where water delivery is impractical.

In 1985, according to the government, about $4,700 was budgeted for every man, woman and child on the peninsula. The development committee, with TTI's management skills, claims to have accomplished in five years the goals of two five-year plans.

"Fortunately, basic infrastructure is finished now," said Dymond. "The pace is less frantic now."

"The people are working now," he added.

Tribal rivalries have been quelled. Bukha, a town on the west coast, had been so isolated that it gave its allegiance to the United Arab Emirates until four years ago. Now a road goes there. It is the site of another small military installation, and its people are Omanis once again.

Dymond appeared relaxed and confident as he handled constant phone calls to his office asking for decisions about a variety of matters, including laying underground phone lines and a ceremony for the governor to turn on the new street lights in Khasab.

"It's quite an achievement that's been made here," he said with a smile.