Osama bin Laden’s Al Qaeda terrorist organization may use tactics honed in Iraq to launch an attack in America, according to domestic intelligence agencies. The group “is and will remain the most serious terrorist threat to the homeland as its central leadership continues to plan high impact plots while pushing” other extremist Islamic terrorists to “mimic its efforts,” the 16 American intelligence agencies said in a report released yesterday in Washington.

“As a result, we judge that the United States currently is in a heightened threat environment,” the agencies reported.

The report comes almost six years after America invaded Afghanistan with the express purpose of wiping out Al Qaeda after the September 11, 2001, attacks on America.

The findings show that the Bush administration was wrong to move forces from Afghanistan to invade Iraq, the chairman of the House Armed Services Committee, Rep. Ike Skelton, said.

“We should have concentrated our efforts on Al Qaeda in Afghanistan from the beginning,” Mr. Skelton, a Democrat of Missouri, said in a statement sent by e-mail. “We must responsibly redeploy our troops out of Iraq” and “concentrate our efforts on Afghanistan and the Al Qaeda terrorists who attacked us on 9/11.” The report says Al Qaeda is gaining strength in the “safe haven” it has established in tribal areas in western Pakistan along the Afghan border and is putting in place a stable leadership with top lieutenants.

Senior intelligence officials, in a briefing for reporters, said agreements that President Musharraf of Pakistan made with tribal leaders backfired, and General Musharraf hasn’t shown the ability or will to evict the terrorists.

“The existence of this safe haven is critical to Al Qaeda’s capability to plan, to train, to organize,” the top American intelligence analyst, Thomas Fingar, said. Al Qaeda can “hide in plain sight because of sympathy for the ideology, for the groups, for the goals among the local population,” he said.

This resurgence is a reversal of Al Qaeda’s condition after the American-led invasion of Afghanistan in 2001, Director of National Intelligence Michael McConnell said.

“They were close to being destroyed,” he said in a speech to intelligence professionals yesterday in Washington.

The report says that Al Qaeda’s association with its affiliate, “Al Qaeda in Iraq,” will help it raise money and recruit and indoctrinate terrorist operatives.

The finding that Al Qaeda will leverage “contacts and capabilities” gained in Iraq to attempt attacks on U.S. soil is released as President George W. Bush tries to fend off efforts by Democrats and a growing number of Republicans in Congress to set conditions for withdrawing troops from Iraq. House Republican Conference Chairman Adam Putnam of Florida said the report shows the need to keep fighting Al Qaeda in Iraq.

Al Qaeda in Iraq “has explicitly stated its intent to launch devastating attacks on our homeland,” Putnam said in an e-mailed statement. “This is certainly not the time for our resolve to give way to timidity.”

White House spokesman Tony Snow said the report’s release wasn’t timed to have an impact on the debate in Congress.

The National Intelligence Estimate, which took three years to produce, goes “through a very long process of scrubbing,” he told reporters in Washington. “When it is ready, we put it out.” Charlie Allen, the Homeland Security Department’s senior intelligence official, told reporters there is no specific threat now to America.

America remains at condition “yellow,” or elevated risk, for general threats and “orange,” or high, for the airline industry.

Mr. Allen and other senior American intelligence officials released declassified “key judgments” of the report today. These assessments include:

• Al Qaeda probably will continue to seek nuclear, chemical, biological or radiological weapons and “would not hesitate to use them” to inflict mass casualties on “prominent political, economic and infrastructure targets.”

• Radical Islam is spreading throughout the world and within America. Europe faces a worse problem with homegrown radicals.