But the document said that there were cases in which such approval was not required: when American forces were in hot pursuit of former members of Mr. Hussein’s government or terrorists.

Approval by the defense secretary “is not required to conduct uninterrupted pursuit and engagement of positively identified former regime military aircraft, terrorist and senior [former] military leadership and senior nonmilitary elements of former Iraqi regime command and control across international borders,” the document said.

It stated that the American commander engaged in the pursuit, however, should consult with top commanders in Baghdad, “time permitting.”

It is not known if the authority to conduct hot pursuits across the Iranian and Syrian borders was ever used or what authority exists today. In October 2005, The New York Times reported that there had been a series of clashes between Army Rangers and Syrian troops along the border with Iraq. According to the 2005 document, American forces were also authorized to respond to a “hostile force” that used Syrian or Iranian territory to attack American troops in Iraq or that posed an “imminent threat” to American operations there. They were instructed to consult with a senior American commander if there was time.

Apparently in a carryover from the intelligence failures of the Iraq invasion in early 2003, the document says the United States Central Command, which oversees operations in the Middle East, gave American commanders in Iraq the authority to attack mobile “W.M.D. labs”; such labs for making germ weapons were later determined not to exist.

The 2005 document also referred to a Central Command list of the “hostile forces” that may be “engaged and destroyed.” It focused heavily on Mr. Hussein’s former security forces, like the Special Republican Guard and members of the Baath Party militia that were said to have shifted from “overt conventional resistance to insurgent methods of resistance.”

Reflecting the clash the year before between American forces and Mr. Sadr’s militia, the document said the militia and other armed supporters of the cleric had also been on the list of paramilitary forces deemed to be “hostile.” L. Paul Bremer III, the head of the American occupation authority in Iraq until June 2004, had branded Mr. Sadr an outlaw, and an Iraqi judge had issued a secret warrant for his arrest.

But a truce was later worked out with Mr. Sadr, and Iraqi politicians sought to bring him into the political process. Apparently as a result of those developments, the rules of engagement were modified. Referring to Mr. Sadr and the Mahdi Army, the document says: “Their status as a declared hostile force, however, is suspended and such individuals will not be engaged except in self-defense.”