WASHINGTON — The Pentagon defended its decision to keep Pearl Harbor Naval Shipyard open as a military judgment call based on the shipyard's strategic location and its ability to work on a variety of ships.

The shipyard is strategically located to support the Defense Department's current and future missions in the Pacific, the Pentagon explained in a letter to the Base Realignment and Closure Commission that was made public yesterday.

"Loss of the critical asset will have an adverse impact on operational war fighting capability, training and readiness," the Pentagon's letter said.

Despite what appears to be a strong argument defending the Pentagon's stand, several military analysts said it might not be enough to keep the shipyard from being added to the list of military installations across the country that an independent panel is studying for possible closures and realignments.

The Pentagon's letter comes in response to a July 1 question from the panel asking why the Pentagon chose to recommend closing Portsmouth Naval Shipyard in Kittery, Maine, instead of the shipyard at Pearl Harbor when scores for military value favored Portsmouth.

In its letter, the Pentagon said that while Pearl Harbor had a slightly lower quantitative score for military value, it represented a higher overall military value for the Navy.

That came from the shipyard's "critical geographical location" — next to a significant portion of the Navy's fleet and its position in the central Pacific. In addition, it has the ability to dock a nuclear-powered aircraft carrier, said the letter from Gordon England, acting deputy defense secretary.

Working against Pearl Harbor is a military cost analysis that shows realigning the shipyard's depot function would save more money than realigning the one at Portsmouth. Another part of the analysis found that closing Portsmouth would save about the same as realigning Pearl Harbor's depot function.

Representatives of the Defense Department are scheduled to appear before the BRAC Commission Monday morning.

They will be joined by members of the Government Accountability Office, which studied the process that the Pentagon used to develop its recommendation, and the Oversea Basing Commission, which issued a report concluding that an additional carrier group, possibly based at Pearl Harbor, may be needed in the Pacific.

Sen. Dan Inouye, D-Hawai'i, said the Pentagon's arguments in favor of Pearl Harbor were "a fact-filled and persuasive justification" for not closing or realigning the shipyard. They "further strengthen the already strong position" that the state's congressional delegation and governor, the mayor of Honolulu and Hawai'i business leaders have taken, he said.

"Pearl Harbor Naval Shipyard, given its capabilities and strategic location in the Asia-Pacific region, provides an invaluable and much needed service for our Pacific fleet and our nation's defense," said Inouye, the top Democrat on the Senate Appropriations defense subcommittee. "With this additional information ... I believe any argument for adding the Pearl Harbor shipyard to the list of facilities recommended for closure or realignment has been greatly weakened."

Rep. Neil Abercrombie, D-Hawai'i, a senior member of the House Armed Services Committee, said the case for the shipyard boiled down to the same thing that real estate agents tell their clients.

"Location, location, location," Abercrombie said. "That's the essence of Secretary England's reason for retaining Pearl Harbor shipyard and he's absolutely right."

Rep. Ed Case, D-Hawai'i, said the question before the commission is "Are you going to out-military the military on a military strategic judgment?"

"I think that is a hard thing to do, but the BRAC Commission both present and past have demonstrated that can happen so it's not over by any means," he said.

Defense analyst Christopher Hellman of the Washington-based Center for Arms Control and Non-Proliferation said the Pentagon's analysis shows that there was a photo finish between Pearl Harbor and Portsmouth as far as military value was concerned.

"What was the determining factor was geography," he said. "That's not terribly surprising given the fact that the military is orienting itself away from Europe and towards the Pacific."

Defense analyst Robert Gillcash, a senior adviser with the legal firm McKenna, Long and Aldridge in Washington, said it was too early to assess whether the Pentagon's defense of Pearl Harbor in the letter was enough to keep the shipyard off the commission's list of possible closures and realignments.

"What I do think is that if further debate is needed, then that will be drawn out between now and September and that would also require adding Pearl Harbor to the list," he said.

Jim Tollefson, president of the Chamber of Commerce of Hawai'i, described England's letter as "very supportive."

"We're very pleased the Defense Department has stepped up with their strong support," he said.

On Monday, Inouye, Gov. Linda Lingle and Mayor Mufi Hannemann will meet with some of the members of the commission to offer further explanations of why Pearl Harbor should remain open.

On Tuesday, the commission will decide whether the Pearl Harbor Naval Shipyard should be added to the list of facilities to be considered for closure.

"If it is not on the list, we will be very pleased," Tollefson said.

"If it is placed on the list, we are already prepared for next step."

The chamber's military affairs council, which Tollefson said includes several senior retired military officers, "including four-star admirals," is working closely with other state and Pearl Harbor officials. The group is being advised by William J. Cassidy Jr., who was deputy assistant secretary of the Navy from 1994 to 2001, during the last round of BRAC closures to affect Hawai'i.

If Pearl Harbor is added to the list, Tollefson said, Hawai'i and shipyard officials will prepare for further hearings and for an on-site visit that the commission will make to the shipyard.

"We'll have the proper people making the proper presentations," he said.

Jason Holm, Pearl shipyard spokesman, said federal workers there support the original recommendation made by the Defense Department on May 13, which left the shipyard off the list of possible closures.

"We agree with the letter in the same way that we agree with the Department of Defense's original recommendation," he said.

As federal workers, however, they will do whatever is asked of them by the commission.

"We'll support the process," he said. "We'll provide the BRAC with all the data they need to formulate their decision."

They'll do it, he said, while continuing to do their jobs for the Navy.

"Our focus," he said, "is on what we can control, and what we can control is how we get ships back to the fleet to keep our nation safe. That is our history, and that is our reality."