The U.S. Army Reserve is leveraging real-world exercises to build combat readiness, said Lt. Gen. Robert Harter, chief of the Army Reserve and commanding general of U.S. Army Reserve Command.

With new and advancing threats increasing the volatility of warfare across the world, the Army Reserve must operate as a fully integrated part of the Total Army, and to maintain that integration, its soldiers and leaders must make full and smart use of the 39 annual training days it has, Harter said Nov. 18 at a Coffee Series event hosted by the Association of the U.S. Army.

“My message to my team, and my team gets it, my message to my [active duty] teammates is, you go, we go, and we’ve got to be ready,” Harter said. “We are not complementary. We are needed right away, and so we have 39 days a year to build readiness where we might have young men and women out the door, so right now that’s what we’re driving on.”

Harter emphasized the Reserve’s theater-opening sustainment capabilities that include medical, signal and engineer soldiers and units. He also pointed out that the Reserve handles 99% of line haul bulk petroleum for ground and aerial platforms. The other 1%, he said, resides in the Army National Guard.

“Our purpose in the United States Army Reserve is to [provide] combat-ready soldiers and formations at time of need, so we’re trying to channel all our energy into driving on that readiness 39 days a year,” Harter said.

To provide realistic training scenarios, Army Reserve units are taking part in exercises with the Regular Army, the Army National Guard and joint forces at the National Training Center at Fort Irwin, California, and the Joint Readiness Training Center at Fort Polk, Louisiana.

Harter highlighted Mojave Falcon as an example of the collective training partnerships that are being built with the Army’s other two components. The exercise in May and June 2025 involved some 10,000 Army Reserve soldiers who supported the exercise from Fort Hunter Liggett, California, a training area about 300 miles north of the National Training Center, and at ports in Long Beach, California.

Coming up in June at the Joint Readiness Training Center is Operation Sentinel Justice, which will see Reserve units supporting the Virginia National Guard’s 116th Infantry Brigade Combat Team, which transitioned to the 116th Mobile Brigade Combat Team in October as part of the Army’s continuous transformation efforts.

Reserve units will support the exercise at the training center, but also from Camp Shelby, Mississippi, which will introduce “real-world distances and driving fuel and ammunition” into an exercise that will “build that multi-component integration,” Harter said.

“It’s train as you fight because … who knows how much time we’ll have,” Harter said, recalling the surprise of the Sept. 11, 2001, attacks and the Army’s subsequent immersion in combat. “We better be ready to go, so let’s put our energy into it.”