FORT RILEY, Kan. – For more than a decade, troops here have been schooled in counterinsurgency.

"Mission-specific" training, they call it: going house to house, busting down doors, rooting out terror cells, recognizing crude explosives. Now, after a pair of mission-specific wars, an Army in transition aims to get back to the future.

The training needed to fight full-scale, more conventional battles has suffered, Army leaders say. So Fort Riley is putting soldiers such as Staff Sgt. Gilbert Monroe back into big tanks and simulating wars on a scale grander than Iraq or Afghanistan.

"This is what I signed up for," Monroe said.

He began his military career 14 years ago in an M1 Abrams tank. But he spent tours in Iraq commanding more nimble armored vehicles that lacked the heft to blast a target from 2 miles out.

With Americans still assessing what was gained from fighting two drawn-out conflicts at the same time, are they ready to start thinking about the next war — maybe even The Big One?

"You hope it wouldn't be World War III, but you have to prepare for the worst," said Lt. Gen. Robert B. Brown, commanding general of the Army's Combined Arms Center at Fort Leavenworth. "We need to be ready to play against the pro teams, not just the amateurs."

By that he means a nation such as North Korea, even Russia. A "pro team" could even be a band of radicals with the means to acquire nationlike resources in a hurry — such as those fighters who call themselves the Islamic State in Iraq and the Levant, recruiting through the Web's reach.

In Army-speak, the training needed to fight that brand of enemy is shifting away from "mission-specific" toward "decisive action."

And that requires the reacquainting of soldiers with epic battle plans featuring tanks, surface-to-air missiles, Apache choppers and military precision exercised over a broad and rugged terrain.

"That skill set has perished," said Timothy Livsey, Fort Riley's deputy garrison commander. "It's a paradigm shift for the Army," he said. "With Iraq and Afghanistan, it was all about COIN — counterinsurgency. We still need to train for that. But we also have to get back to bread-and-butter skills such as precise artillery, precise gunnery."

Fort Riley officials say decisive-action training blends yesterday's emphasis on battlefield prowess with the people skills required of troops more recently focused on counterinsurgency.

At a time when U.S. military action has become defined by targeted airstrikes, ships jockeying in the South China Sea and a reluctance to place boots on the ground, the Army is seeking to reassert itself on the strategic stage.

Now facing steep troop reductions planned by the Pentagon, "the Army really is looking for a strategic framework in which to remain relevant," said Kelley Sayler of the Center for a New American Security, an independent research organization.

"And you do need to train for the prospect of an epic war, even if there's a low likelihood of it happening," Sayler said.

Nora Bensahel, a defense policy expert at American University, agreed. "You have to prepare for the full spectrum," she said.

Generations of U.S. military planners have gravely miscalculated that the next war would be like the last, she said. "You just don't know what the next conflict will entail."

Don't think of the activities at Fort Riley as training for a conventional war, said Brown of the Combined Arms Center.

"A nation-state fighting against another nation-state would be so complex these days, so unlike World War II, you could hardly make a comparison," he said.

Future wars wouldn't compare even with Operation Desert Storm, the 1991 land assault in which a multinational force drove Iraqi troops out of Kuwait. Brown said technological leaps since then, plus threats posed by cyberattackers, have transformed conventional battle plans.

"No enemy today would be stupid enough to allow us months and months to build up forces," as was the case in Desert Storm, he said.

Fort Riley this year became the first in the Army to use gaming software developed at Fort Leavenworth's simulation laboratory. It allows moving soldiers to become their own fighting avatars, surrounded by a virtual battleground they view through helmets.

"You become immersed," said Bill Raymann, chief of training at the fort's Close Combat and Tactical Training campus. "If a simulation is done correctly, it'll take the brain about 15 seconds to adjust back. You walk out the door surprised: 'Oh, I'm really in Kansas.' "