Vice Adm. Michael J. McCabe, commander of the U.S. Navy's 3rd Fleet, said 95 percent of global trade involves sea transport. Terrorists' use of sea lanes is a big concern.

"Some 46,000 ships of size pass through 4,000 ports, and frankly, we don't have the greatest picture of what happens on the sea, ... So I think it's very important, particularly in the Pacific, that the navies of the world get together and work together and can communicate well together as we focus on countering the terrorist threats ... in terms of the movement of weapons, people, drugs and illicit trade," McCabe said yesterday.

The world's navies need to be able to communicate more broadly and share information more rapidly than they do now, McCabe said. "So that's one of the things that you'll see us pushing."

The biennial RIMPAC war games, held since 1971, this year include at least 16 nations, more than 40 ships, seven submarines, 100 aircraft and almost 18,000 military personnel.

The San Diego-based aircraft carrier USS John C. Stennis, which pulled into Pearl Harbor yesterday with 5,000 crew members and air personnel, will serve as the multinational force command ship for the exercise that runs through July 27.

RIMPAC includes sinking the decommissioned destroyer USS Decatur, the appearance of a more-than-300-foot "wave piercing" catamaran cargo vessel, a Marine amphibious landing at Bellows, and aircraft ranging from helicopters and P-3 Orion sub hunters to fighters and a B-52 bomber.

Canada's contingent includes four ships, CH-124 Sea King helicopters, and two maritime patrol aircraft after a "pretty low level" of participation two years ago because of war-related deployments, said Commodore Roger Girouard.

"This year's RIMPAC for us is an opportunity," Girouard said.

"Every nation has response constraints whether it's (personnel) tempo issues or the cost of gas this year. But you've also got national sort of agendas, and in my case that's building a deployable task group. RIMPAC gives me the springboard to do that."

A mass casualty drill on board the 1,092-foot Stennis, will test the ship's ability to deal with attacks from missiles and mines as well as a chemical, biological or radiological attack.

McCabe said it's hard to determine the cost of RIMPAC.

All countries have an operating budget and their navies spend time at sea.

"So the normal operations that you have would cover that kind of expense," he said. He added that he prefers to put it in terms of cost avoidance — by working together to avoid losing lives and equipment.