DILLINGHAM AIRFIELD, Hawaii—Capt. Sam Soliday is standing in front of a Black Hawk on a gravel airstrip across the street from Oahu’s picturesque northwest coast, a “jungle” patch velcroed to the sleeve of his combat shirt. He’s one of more than 5,000 U.S, Indonesian, Thai, British, and New Zealander troops spread out on islands from Hawaii to Palau in the western Pacific for an enormous training exercise that simulates “large-scale conflict against a peer adversary in jungle and archipelagic conditions.”

That’s a long way of saying they’re preparing for a fight with China in the Pacific, even if Army officials prefer to keep it officially vague. But for Soliday, the main difference from previous training exercises is the scenario: an inter-island conflict.

“As a U.S. Army, we have not seen a conflict like this since the World War II era,” said Soliday, an intelligence officer. And there is an “added layer of complexity to the problem set that involves moving assets from different islands, crossing wet gaps. And the aviation task force really provides the support to enable those operations. And the different types of terrain that can vary on islands can go from steep gulches to flat, desolate areas. So operating in an austere environment that these islands provide really, really truly is the best way to train the light fighter, as well as you know, a combat aviation brigade.”

In recent decades, the U.S. Army has done exercises of this scale at its training facilities in California and Louisiana. But this one—the first since the Joint Pacific Multinational Readiness Center was validated and certified by the Pentagon in June as a joint national training capability—is critical to preparing for conflict in the Indo-Pacific region, said Gen. Charles Flynn, commander of U.S. Army Pacific.

Previously, “we would pack up an entire division’s worth of equipment, and we would sail through the Panama Canal” to get to Louisiana, Flynn said, which meant soldiers were separated from their equipment for “a couple of months.”

“We cannot afford to be going out of this region. We have to stay in the region,” he said. “And having an environment like this—this is not Louisiana. And so, we’re using watercraft, we’re using six C-130s and nine C-17s from [Pacific Air Forces].” 

Pacific Fleet, Special Operations command, and U.S. Marine Corps assets are also involved in the exercise, dubbed JPMRC 24-01 and held from Oct. 20 to Nov. 10.

“There’s all these benefits of having the joint force in Hawaii,” Flynn said. “This is enormously important for the joint force, because I’m not aware of anywhere else, at least in the Army, where you actually get this amount of joint tactical training.”

For Chief Warrant Officer 3 Zachary Francis, a senior instructor pilot, said the exercise is about “building combat power for training purposes, so if there’s ever a crisis or conflict in the world, we’re ready to go.”

Francis deployed to Afghanistan, but said flying in Hawaii is different because of the terrain—the ocean, mountain ranges, and even a desert environment on the island of Hawaii. 

“From that training perspective alone, it’s super fantastic that we get to train out here, and we get the actual real-world training value of operating in between island chains,” he said.

A short drive away from Francis and Soliday, a small group of artillery soldiers is huddled around a howitzer named “Chop Suey,” shielded from the sun by camo netting. Maj. Ryan Yamauchi, the 25th Infantry Division’s artillery executive officer, said operating in the jungle is a “huge shift” from the urban environments and open deserts of Iraq and Afghanistan.

“Operating in a jungle has really kind of taught us to…modify some of the tactics, techniques and procedures of how we employ artillery,” he said. “A lot of it is massing, so meaning as many howitzers as we can, and not just howitzers,” but also rocket capabilities to mass on target.

Down a red clay dirt road, behind a tangle of concertina wire, Maj. John Azbill is overseeing communications from a camouflaged command post. Azbill has only been on the island a few months, but learned quickly that electromagnetic signature radio waves “aren’t a fan” of the jungle environment.

“In the desert, there is no interruption, there is no interference, if you will, from the terrain.…The desert is wide open, and communication signals travel a long way. So it’s very simple for us to operate. Now, as we kind of shift and pivot to the Pacific, it’s a lot different terrain, so the environment is going to be much more challenging for us as a Signal Corps and a signal community,” he said.

Despite the scenarios and messaging that seem to point directly to China, Col. R.J. Garcia said the training exercise was not designed for a particular threat. Instead, said the 25th ID deputy commander for support, the idea was to “challenge the leadership, from soldier all the way to the highest levels of decision-making, so they’re more agile and ready to go regardless of the adversary.”

And, Garcia said, training in Hawaii makes it possible for partner nations and the other services to participate, and “it trains us in the environment we’re going to fight in.”

Partnering for the fight

A few days later, in a grassy clearing framed by lush mountains, Thai soldiers, infantry troops from the Royal Regiment of Scotland and U.S. Army advisors prepared an attack. In this training scenario, they were helping a fictional country defend itself against an aggressor.

Regardless of the scenario, “It’s important that the U.S. Army has confidence that the partners can work with us in terms of their techniques, tactics, procedures, and equipment, but also that the partner force has confidence that they can work with us. That way we have a joint front against the enemy,” said Capt. Will Sherwood, maneuver advisor team leader with 5th Security Force Assistance Brigade.

Maj. Matthew Lensing, a 5th SFAB company commander, said forging that trust and confidence now is essential.

“Especially in this region that we’re so focused on, we know how long it would take for the U.S. to build up forces in the Indo-Pacific…We would need help. And that’s why having a group of partners that want to partner with us already available, and they feel that the U.S. is their partner of choice. That is our mission. And that’s how we meet the intent of our U.S. Army Pacific commander to deter war, by building a strong network of partners that want to work with us and train with us in these events.”

Lt. Toby Johnstone, a platoon commander with the Black Watch, 3rd Battalion, Royal Regiment of Scotland, is part of a small team training the Thai soldiers on light infantry tactics. It has its difficulties, he said, particularly since there are only about five English speakers out of 90 troops, but the rapport and communication have improved over the course of the exercise. The experience and relationship-building—with American and Thai soldiers—are also valuable, he said.

Capt. Supathin Bunsang, a platoon leader for Thailand’s Long Range Reconnaissance Company 6, told Defense One through a translator that the training is quite different from exercises in his home country, where training is scripted and predictable.

Bunsang said he’d bring back to other soldiers in Thailand “the training of being ready for any situation, ready for surprise attack, ready for like, anything unpredictable.”

‘A joint theater’

The Pentagon has made clear that the U.S. military’s “pacing threat” is China—and Flynn says he’s seen the Chinese engaged in “irresponsible and insidious behavior” in the region.

“That’s the bad news. The good news is that I’m also seeing an increase in multilateral and multinational exercises, tenfold,” he told a small group of journalists at Schofield Barracks. “This is often referred to as an air and maritime theater, but it’s not. It’s a joint theater. It’s got joint challenges, joint multinational challenges, and we’re only going to solve it with joint and multinational solutions.”

And the U.S. Army will play a key role in those solutions, as the “backbone of the joint force,” Flynn said.

“I think that what the Chinese have created is a [anti-access and area denial] arsenal that is primarily designed to defeat air and maritime power, and secondarily… to deny, degrade, and disrupt space and cyber,” Flynn said. “It is not designed to find, fix and finish distributed, mobile, lethal, fixed, semi-fixed, and reloadable land forces that can hide in the clutter, because we can hide in the clutter.”