Washington ? The Bush administration is developing a parallel legal system in which terrorism suspects – U.S. citizens and noncitizens alike – may be investigated, jailed, interrogated, tried and punished without legal protections guaranteed by the ordinary system, lawyers inside and outside the government say.

The elements of this new system already are familiar from President Bush’s orders and his aides’ policy statements and legal briefs: indefinite military detention for those designated “enemy combatants,” liberal use of “material witness” warrants, counterintelligence-style wiretaps and searches led by law enforcement officials, and, for noncitizens, trial by military commissions or deportation after strictly closed hearings.

Only now is it becoming clear how these elements could ultimately interact.

For example, under authority it already has or is asserting in court cases, the administration, with approval of the special Foreign Intelligence Surveillance Court, could order a clandestine search of a U.S. citizen’s home and, based on the information gathered, secretly declare the citizen an enemy combatant, to be held indefinitely at a U.S. military base. Courts would have very limited authority to second-guess the detention, to the extent that they were aware of it.

Administration officials say the parallel system is meant to be used selectively, as a complement to conventional processes, not as a substitute. But, they say, the parallel system is necessary because terrorism is a form of war as well as a form of crime, and it must be punished after incidents occur while being prevented and disrupted through the gathering of timely intelligence.

At least one American has been shifted from the ordinary legal system into the parallel one: alleged al-Qaida “dirty bomb” plotter Jose Padilla, who is being detained at a Navy brig, without the right to communicate with a lawyer or anyone else. U.S. officials have told the courts they can detain and interrogate him until the executive branch declares an end to the war against terrorism.

The final outlines of this parallel system will be known only after the courts, including probably the Supreme Court, have settled a variety of issues being litigated, but the prospect of such a system has triggered a fierce debate.

Civil libertarians accuse the Bush administration of a power grab that will erode the very rights and freedoms that terrorists are trying to destroy.

“They are trying to embed in law a vast expansion of executive authority with no judicial oversight in the name of national security,” said Kate Martin, director of the Center for National Security Studies, a group that has challenged the administration approach.

Administration officials say they are acting under ample legal authority derived from statutes, court decisions and wartime powers that the president possesses as commander in chief under the Constitution.

“When you have a long period of time when you’re not engaged in a war, people tend to forget, or put in backs of their minds, the necessity for certain types of government action used when we are in danger, when we are facing eyeball to eyeball a serious threat,” said Solicitor General Theodore Olson, who leads the administration’s anti-terrorism legal team.