I Corps and allies demonstrate joint force readiness during Yama Sakura 85

CAMP ASAKA, Japan — Yama Sakura 85, a multilateral command post exercise spanning 10 days, marked several significant accomplishments demonstrating the capability and interoperability of I Corps and its allied forces during this first-ever trilateral iteration.

YS 85 is a scenario-driven command post exercise focused on defending Japan's territorial sovereignty from hypothetical adversaries and is integral to U.S. Army Pacific’s Operation PATHWAYS. The exercise emphasized the importance of cohesive multinational military efforts across the Indo-Pacific as the Australian Army participated in the exercise for the first time.

This 43rd iteration of YS included a range of simulated challenges, including safely evacuating over 15,000 civilians and countering an active disinformation campaign while simultaneously fighting a well-equipped adversary with combined arms capability.

Approximately 1,300 U.S. troops from Joint Base Lewis-McChord, Washington and Joint Base Elmendorf-Richardson, Alaska, deployed to four distinct locations in Japan: Camp Asaka in Tokyo; Camp Higashi-Chitose in Hokkaido Prefecture; Camp Sendai in Miyagi Prefecture; and the U.S. Army’s Camp Zama in Kanagawa Prefecture demonstrating operational flexibility of I Corps and its subordinate units.

This year, the exercise also highlighted the logistical agility of I Corps sustainers to coordinate and move forces and equipment across a vast distance west of the international date line, showcasing the readiness and mobility of I Corps and its forward posture in the Indo-Pacific.

“We achieve posture by campaigning as we do with Operation PATHWAYS,” said Lt. Gen. Xavier Brunson, the commanding general of America’s First Corps.

“That allows us to seamlessly integrate or insinuate ourselves into their processes, whether here or abroad, and be prepared to show up, ready to operate alongside a partner,” he added. “The only way we’re going to be successful in moving forward is if we continue to drive to be beside our partners in the region.”

A pivotal aspect of YS 85 was further refining distributed command and control, which is essential for coordinating complex military operations from separate command nodes in different countries. In tandem with the Japan Ground Self-Defense Force and the 1st (Australian) Division, I Corps and its subordinate units — the 7th Infantry Division, 11th Airborne Division, 17th Field Artillery Brigade, 3rd Multi-Domain Task Force, 201st Expeditionary Military Intelligence Brigade, and the 593rd Expeditionary Sustainment Command — along with U.S. Army Japan forces, demonstrated cohesion in their decision-making capabilities despite operating from different locations and often in different time zones.

“This year’s Yama Sakura has exemplified how robust [command and control] contributes to a unified approach, ensuring that we truly work together toward shared objectives. This is essential for maintaining readiness and reinforcing our commitment to peace and stability in the Indo-Pacific region,” said Brunson.

“It enables us to synchronize our efforts, make informed decisions quickly, and respond to dynamic situations with agility,” he added.

The partnership and integration between the three nations and approximately 7,000 service members of all ranks during this command-post exercise was a significant milestone demonstrating regional cooperation and strategic alignment.

“This exercise emphasizes a continued commitment by Japan, the U.S. and Australia to work towards our shared vision of a stable, prosperous and open Indo-Pacific region,” said Mag. Gen. Scott Winter, commander of the 1st (Australian) Division.

“Speaking on behalf of the 1st (Australian) Division, I can also say we have learned a great deal from our partners. We greatly appreciate that regardless of rank, age or experience, our soldiers and officers worked proactively together to achieve mission success,” he added.

Other focus areas within the exercise were the collaboration between warfighting functions, including the sustainment and protection cells.

“In recent exercises, we’ve seen significant progression in how our Australian and Japanese partners approach Protection as a warfighting function,” said Col. Scott Blanchard, I Corps’ provost marshal and protection director. “At Talisman Sabre, Australia established its first protection cell, a substantial step in their operational development.”

Similarly, the Japanese have made strides in this area during YS 85. “This is the first time the Japanese have formed a protection cell in the manner we are accustomed to, creating an opportunity for a greater degree of shared understanding. These are notable firsts for both nations, symbolizing a continuous evolution in their approach to comprehensive warfighting strategies," said Blanchard.

A benchmark for the sustainment cell is the inauguration of a Japan Ground Self-Defense Force and U.S. Combined Joint Movement Coordination Center. This multilateral team worked through challenges provided by the scenario to secure air, sea and ground transportation of sustainment in a contested near-peer fight. These solutions provided flexibility and responsiveness, allowing both joint task forces to sustain the fight.

While the sustainment and protection warfighting functions demonstrated considerable progress during YS 85, it was not alone in its advancements. Each area of focus within the command post exercise saw significant improvements. From the precise execution of Information operations to the redundant communication platforms and progression of a Mission Partner Environment (MPE) provided for Command and Control, all aspects of a command post were challenged and honed.

A common theme of the exercise was enhancing the ability for the three participating nations to operate across all warfighting functions and take back lessons learned to incorporate in future training events.

Lt. Gen. Royoji Takemoto, commanding general of JGSDF’s Ground Component Command, requested two things at the beginning of the exercise, the “enhancement of the combination between cross-domain operation and multi-domain operation concepts to improve the operational effectiveness” and the “improvement of interoperability.”

During the closing ceremony of Yama Sakura 85, Takemoto reflected on the strengthened bonds and enhanced interoperability among the U.S., Japanese and Australian forces.

“Along with our strong partnership we grew through this exercise amongst Japan, the United States and Australia, let us keep working together to commit to the effort for a Free and Open Indo-Pacific region,” he said.

Since its first iteration in 1982, Yama Sakura, which means “mountain cherry blossom,” has focused on developing and refining the JGSDF and USARPAC’s bilateral planning, coordination and interoperability efforts. For over 40 years, this exercise has demonstrated a continued commitment by both the United States and Japan to work together as dedicated allies in support of the U.S.-Japan security treaty and for continued peace and stability in the Indo-Pacific region.

Exercises like Yama Sakura 85 are crucial in maintaining a high state of readiness, fostering human and procedural interoperability partners and ensuring regional security and stability.