During this year’s Rim of the Pacific exercise, it’s possible for a Japanese soldier to work for an Australian battalion commander who works for a U.S. Marine Corps commander who works for an Australian task group commander who works for a Chilean maritime component commander.

RIMPAC is about interoperability, and it will be played out in big ways at sea, in the air and on the ground through July in and around Hawaii.

And yes, garage door remotes might temporarily malfunction again due to some surface search radar testing in port, the Navy said.

Twenty-five nations, 46 surface ships, five submarines, 18 national land forces, more than 200 aircraft and 25,000 personnel are gathered mainly in Hawaii but also in Southern California for the world’s largest international maritime exercise.

Twenty-six nations were expected, but Brazil, a first-time participant, dropped out at the last minute due to “operational scheduling” issues, the Navy said.

“RIMPAC brings together like-minded nations who value a free and open Indo-Pacific area,” Adm. John Aquilino, commander of U.S. Pacific Fleet, said Thursday at an opening news conference. “It gives us all a chance to increase our interoperability, improve our ability to work together and, most importantly, build trust throughout the nations who participate.”

Aquilino spoke on a Pearl Harbor pier flanked by officers from at least 16 nations and with Indonesian, Korean and Canadian warships as a backdrop.

China was disinvited because of an ongoing dispute over the Asian nation’s island building and militarization of islands in the South China Sea.

However, it and Russia are among nations at the center of some of RIMPAC’s key exercises, which focus on what’s known as “anti-access, area denial” — the ability to use warships, aircraft and long-range ballistic and cruise missiles to thwart entry to a war zone.

One way the United States is fighting back is through what’s known as Multi-Domain Battle — multiple services working together to gain the advantage on land, air, sea, space and cyberspace.

A Muti-Domain Task Force was set up that will oversee Japan and the United States firing missiles from shore at a decommissioned ship July 12.

The Army plans to rapidly deploy a “High Mobility Artillery Rocket System” from an Air Force C-17 cargo aircraft and fire practice missiles.

AH-64 Apache attack helicopters will be paired with Gray Eagle unmanned aerial vehicles at sea to find targets.

“This is a huge event for us, and this is just the start,” said Army Col. Christopher Wendland, who commands the 17th Field Artillery Brigade out of Washington state and is also the Multi-Domain Task Force pilot program commander.

Wendland said part of the formula is interconnecting sensors to find an enemy ship and, “How do we become part of the Navy’s network? So then when they ask for something, it’s not just Navy options. There are Army options that can support it.”

Vice Adm. John Alexander, commander of the 3rd Fleet in San Diego, which plans RIMPAC, said the Multi-Domain Task Force represents “the first time we’ve done something like this in RIMPAC. So we’re looking to expand this in 2020.”

Alexander also is the combined task force commander for RIMPAC.

The exercise will include a B-1 bomber firing a Long-Range Anti Ship Missile at a ship. Other aircraft will fire missiles at the vessel, the submarine USS Olympia out of Pearl Harbor will fire a Harpoon missile through a torpedo tube, and the Australian submarine HMAS Rankin will fire a torpedo.

“So there’s multidomain battle going on the entire time,” Alexander said.

The Pearl Harbor subs USS Illinois and USS Hawaii, both newer Virginia- class vessels, also are participating.

Rear Adm. Daryl Caudle, who commands the U.S. Pacific Fleet submarine force, said Harpoon use on subs “is a capability we decommissioned about 10 years ago, and we’re bringing it back to give us some anti-ship cruise missile capability. We’re testing that new capability again.”

The aircraft carrier USS Carl Vinson and its escorts will be searching for submarines, and the submarines will practice their own anti-submarine warfare.

Ship-passing skills and gunnery at sea will be practiced, and RIMPAC will have a disaster assistance exercise for an earthquake and tsunami.

Brig. Gen. Mark Hashimoto, Fleet Marine Force commander, said 2,300 U.S. Marines will be participating alongside another 700 marines or soldiers from other nations as part of a Marine Air-Ground Task Force.

Marine Corps surface and air assaults from the sea will occur on Kauai and at Dillingham Airfield, Bellows, and on the Marine Corps base, and will be worked into the larger naval battle plan that begins with a belligerent nation, a period of force buildup and a multinational military response, Hashimoto said.

Pohakuloa Training Area on Hawaii island is part of the mix with ship-based aircraft providing close-air support for Marine Corps artillery units working with Indonesian and Australian counterparts.

RIMPAC, meanwhile, keeps growing.

“Just to put it in perspective, in 2008 we had 10 participating nations in RIMPAC,” Alexander said. “It’s 2018 and we’ve got 25, and by 2020 we’re expecting probably close to 30.”