WRIGHT-PATTERSON AIR FORCE BASE, Ohio — President Bush said yesterday that the yearlong increased American troop deployment in Iraq had allowed the country to “restart political and economic life” and take on a greater role in its own reconstruction while building a modern democracy on “the rubble of three decades of tyranny.”

But he made clear his readiness to delay the withdrawal of American forces, saying that as he considered his next steps, he would remember that “the progress in Iraq is real, it’s substantive, but it is reversible.”

And in an apparent jab at political critics who he said have refused to acknowledge the achievements he sees, the president said that “now that political progress is picking up, they’re looking for a new reason” to call for retreat.

Accusing some members of Congress of “hectoring” Iraqi leaders, he said: “They claim that our strategic interest is elsewhere, and that if we would just get out of Iraq, we could focus on the battles that really matter. …”

“If America’s strategic interests are not in Iraq … then where are they?” he asked.

The speech was Mr. Bush’s third over the past three weeks intended to present a broad look at American policy in Iraq, the course of the war, and the conditions on the ground five years after America invaded to overthrow the government of Saddam Hussein.

Bush spoke to about 1,000 people, many of them Air Force personnel, at the National Museum of the United States Air Force at Wright-Patterson Air Force Base, on the outskirts of Dayton. He stood between an F-86 of Korean War vintage and a current fighter jet, the F-22, with a Predator drone displayed from the ceiling of the museum hangar and a B-52’s menacing presence to the side.