WASHINGTON (AP) -- Attorney General John Ashcroft aggressively defended stern law enforcement measures in the wake of terrorist attacks and suggested those who question hard-line tactics are aiding the enemy.

Called before Congress Thursday to discuss the detention of hundreds of people without charges and military tribunals for accused terrorists, Ashcroft said, "We need honest, reasoned debate, not fear-mongering."

"To those who pit Americans against immigrants and citizens against noncitizens, to those who scare peaceloving people with phantoms of lost liberty, my message is this: your tactics only aid terrorists for they erode our unity and diminish our resolve," he said. "They give ammunition to America's enemies and pause to America's friends."

His defiant defense of the administration's law enforcement strategy seemed to catch Democratic critics off guard.

Sen. Patrick Leahy, chairman of the Judiciary Committee, told Ashcroft, "The needs for congressional oversight is not to protect terrorists. It is to make sure that our government has good reason before snooping into our bank records, our tax returns or our e-mails."

But several other Democrats took pains to voice support even while asking tough questions, and there were few harsh exchanges. Lawmakers on both sides of the aisle have stressed that they, too, want to see justice done in response to the terrorism of September.

"One option is to call Sept. 11 a fluke and to live in a dream world that requires us to do nothing different," Ashcroft said. "The other option is to fight back."

Holding up an al-Qaida terrorist manual, the attorney general said members of Osama bin Laden's network are exploiting America's openness.

"Terrorist operatives infiltrate our communities, plotting, planning and waiting to kill again," he said.

Ashcroft said the Bush administration's stern new policies are fair. Leahy, however, said Congress should have more say in the new policies.

Ashcroft's appearance came amid growing criticism from Democrats and civil liberties groups about relaxed wiretapping rules, detentions of hundreds of Middle Eastern men whose names have not been disclosed and the Bush administration's plan to use military tribunals to try foreign terrorists.

Buoyed by recent polls showing the public generally supports the tactics, Ashcroft said his critics are uninformed.

"Charges of kangaroo courts and shredding the Constitution give new meaning to the term 'the fog of war,"' he said.

"Each action taken by the Department of Justice as well as the war crimes commission ... is carefully drawn to cover a narrow class of individuals -- terrorists," Ashcroft said.

Sen. Orrin Hatch, R-Utah, said Americans want action.

"Do any members really believe that in this time of crisis, the American people really care whether the attorney general took the time to pick up the telephone and call us prior to implementing these emergency measures," Hatch said.

Sen. Edward M. Kennedy, D-Mass., said the tribunals present "enormous potential for abuse" and pressed Ashcroft for details about what rights defendants would have and whether the trials would be held in secret.

Ashcroft promised "full and fair proceedings" but said military trials would be closed if necessary to protect national security.

"When we come upon those responsible in Afghanistan, are we supposed to read them Miranda rights, hire a flamboyant defense lawyer, bring them back to the United States, create a new cable network of Osama TV or what have you and provide a worldwide platform from which propaganda can be developed?" he said.

As Ashcroft defended the trials, American Bar Association President Robert Hirshon derided them. In a speech prepared for delivery Friday to the National League of Cities in Atlanta, he said, "The Taliban established Star Chambers. They held secret trials followed by public executions. The Iraqis also hold secret trials where execution is all but a foregone conclusion. This is not what America stands for."

Ashcroft would not comment on any legal actions to be taken against John Walker, an American caught with Taliban fighters. But he warned, "History has not looked kindly upon those who have forsaken their countries to go and fight against their countries."

When it comes to listening in on inmates' conversations with their lawyers, Ashcroft said the Justice Department tells all parties that their conversations will be monitored beforehand. He said he is confident that all precautions required by the courts are being taken.

But federal officials are not willing to let terrorists communicate messages of planned attacks to their fellow terrorists through lawyers, as the al-Qaida manual instructs them to, Ashcroft said.

When Sen. Russell Feingold, D-Wis., asked for assurances that detainees will be told of their right to counsel, Ashcroft said "I do not intend to hold individuals without access to counsel. ... I don't believe that we are."