On the wall of Rear Adm. William A. Owens's office at the Pentagon is a Civil War-era photograph of a lot of guys with long faces leaning, squatting and chewing as they hold the reins of the horses their generals will mount when some unspecified war council breaks up.

The photograph is entitled "Horse Holders" and is signed by the men who have occupied the suite that adjoins the office of the secretary of defense over the last two decades.

They have included John A. Wickham Jr., who went on to be Army chief of staff, Colin L. Powell, who is now chairman of the Joint Chiefs of Staff, and Marine Lt. Col. William R. Higgins, who later was kidnapped by Moslem extremists in South Lebanon and killed.

For the last 20 months, the office has been held by Owens, 49, a soft-spoken submariner who leaves next month to take up new duties as commander of the U.S. Sixth Fleet in the Mediterranean.

In March 1989, when then-Rep. Richard B. Cheney (R-Wyo.) was tapped by President Bush as a substitute for the failed nomination of John G. Tower, Owens was the first person from the Pentagon to telephone Cheney, who was surprised to be receiving a telephone call from an admiral he had never heard of making vague offers of assistance.

What Cheney did not know was that Owens was shepherding a mounting stack of paperwork left unattended with the departure of Frank C. Carlucci and the delayed and then canceled arrival of Tower.

In the year since that telephone call, however, Owens has become a trusted and ubiquitous Cheney aide, traveling with him worldwide, feeding him his "Top Secret" daily intelligence briefings, making discreet forays into the bowels of the Pentagon bureaucracy to pluck data the military services might be reluctant to serve up and introducing the boss to the multitrillion-dollar world of weapons, fleets, air forces and armies he oversees.

"I just try to be plugged in to the whole system and try to be the facilitator the guy needs," Owens said. "I can get a lot of stuff for him he cannot get through the system."

One recent morning, Cheney saw a newspaper article asserting that the Navy's Aegis air-defense system could detect the "stealth" aircraft the Pentagon was planning to spend tens of billions of dollars to build over the next decade. Cheney circled the item and told Owens to dig into the Navy to get the facts.

A House member from Idaho wanted help in getting an answer from the Air Force on how it planned to expand and use a sprawling aircraft test range in his state. Owens was sent to find out why the congressman was getting a "non-answer."

Though he wears a Navy uniform, Owens insists that he does not push the Navy agenda to unfair advantage in the secretary's office.

"When I came down here, Admiral {Carlisle A.H.} Trost {chief of naval operations} told me he wanted me to be loyal to the secretary of defense," said Owens, who added that one of the services he has performed for Cheney has been to help explain the culture of the military, which Owens has learned in 27 years of service.

"It's an understanding of where the pet rocks are and where the sensitivities are . . . all the factors that cause the services to act the way they do." Owens accompanies Cheney to a meeting every other week in "the tank" with the four military chiefs, where they hash out the increasingly contentious issues of how to substantially shrink the size of the 2.1 million-member active-duty military.

As Cheney's fiscal targets have become tougher for the military to meet, Owens observed, "the services have been very, very reluctant to offer any innovative help to him."

Owens feeds what he described as a voracious Cheney appetite for data on the massive military bureaucracy inherited just months before the upheaval in Eastern Europe unhinged 40 years of U.S. military planning and strategy. Owens arrives at work at 6 a.m. each day and spends the next 12 to 14 hours reading everything that flows into the secretarial suite.

He focuses on reports, plans and requests forwarded by the service secretaries and the Joint Chiefs and the material that flows in from the inter-agency groups administered by the National Security Council.

In his office, Owens keeps one eye on the panel of lights and phone banks that tell him when the SecDef -- as the shorthand goes for the boss -- is in, when someone is with him and when he is on the phone.

In 20 months, he has filled 17 steno pads with "action" notes on things he needs to do, or the secretary needs.

"I try to read all of the paperwork that comes in," Owens said in an interview. "It amounts to an 18-inch stack a week and I usually stay at night until I've read it all, highlighting things that relate to issues and using paper clips to mark things I think he ought to see."

By the time Cheney arrives between 7:45 and 8 a.m., Owens has moved the inch-thick stack of morning intelligence briefings to Cheney's in-basket. They include overnight summaries from the Central Intelligence Agency and Defense Intelligence Agency. Special reports come in during the day, as one did recently from the CIA updating insights into Warsaw Pact disintegration.

But does Cheney dig into his intelligence basket first thing every morning?

No, said Owens. The first thing he reads is the "Early Bird," a summary of the morning newspapers.