PENTAGON (VOA) - It is an ongoing debate among military officers and defense experts, and Secretary Gates spoke up firmly on one side of it during a speech Tuesday in Colorado.

"Overall, the kind of capabilities we will most likely need in the years ahead will often resemble the kind of capabilities we need today," he said. "The implication, particularly for America's ground forces, means we must institutionalize the lessons learned and capabilities honed from the ongoing conflicts."

Secretary Gates said in the past, counter-insurgency capabilities have been gained and lost, but this time they must be maintained. He criticized those in the U.S. military who are, in his view, overly concerned about restoring such conventional capabilities as tank warfare.

The secretary acknowledged there are what he called "rising and resurgent powers" - an apparent reference to China and Russia among other countries - and he says they must be "watched closely and hedged against." He listed the Persian Gulf, the Korean Peninsula and the Straits of Taiwan as potential flashpoints.

But the secretary said it is "hard to conceive" of any country taking on the United States in a large-scale war, and called the potential risks "manageable." He said the United States has enough combat power in its air and naval forces to deter, or respond to, any "aggression."

"It is true that we would be hard pressed to launch a major conventional ground operation elsewhere in the world at this time," he added. "But where would we sensibly do that?"

Secretary Gates said his analysis has implications for U.S. defense planning and purchasing, and he served notice on all the military services, and their contractors, that, at least as long as he is in office, they will have to address what is called "irregular" warfare.

"Any major weapons program, in order to remain viable, will have to show some utility and relevance to the kind of irregular campaigns that, as I mentioned, are most likely to engage America's military in the coming decades," he explained.

That calls into question several ongoing and very expensive programs, including aspects of the Army's high-technology Future Combat System and the Air Force's new fighter jet, the F-22.

Secretary Gates said one of the most important things the Defense Department must do to prepare for the future is ensure that the people in the U.S. military are properly cared for, and that their morale is not undermined by defeat, as it was after the Vietnam War.

"The risk of overextending the army is real, but I believe the risk is far greater, to that institution as well as to our country, if we were to fail in Iraq," he said. "That is the war we are in. That is the war we must win."

That comment was reminiscent of one by former Defense Secretary Donald Rumsfeld, who famously said in 2004, with regard to the U.S. army's readiness to fight an insurgency in Iraq, "You go to war with the Army you have, not the Army you might want or wish to have at a later time." Secretary Gates was saying the United States must fight, and win, today's war with today's army, and also be better prepared to fight similar wars in the future.