The Pentagon, expanding into the CIA's historic bailiwick, has created a new espionage arm and is reinterpreting U.S. law to give Defense Secretary Donald H. Rumsfeld broad authority over clandestine operations abroad, according to interviews with participants and documents obtained by The Washington Post.

The previously undisclosed organization, called the Strategic Support Branch, arose from Rumsfeld's written order to end his "near total dependence on CIA" for what is known as human intelligence. Designed to operate without detection and under the defense secretary's direct control, the Strategic Support Branch deploys small teams of case officers, linguists, interrogators and technical specialists alongside newly empowered special operations forces.

Military and civilian participants said in interviews that the new unit has been operating in secret for two years -- in Iraq, Afghanistan and other places they declined to name. According to an early planning memorandum to Rumsfeld from Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, the focus of the intelligence initiative is on "emerging target countries such as Somalia, Yemen, Indonesia, Philippines and Georgia." Myers and his staff declined to be interviewed.

The Strategic Support Branch was created to provide Rumsfeld with independent tools for the "full spectrum of humint operations," according to an internal account of its origin and mission. Human intelligence operations, a term used in counterpoint to technical means such as satellite photography, range from interrogation of prisoners and scouting of targets in wartime to the peacetime recruitment of foreign spies. A recent Pentagon memo states that recruited agents may include "notorious figures" whose links to the U.S. government would be embarrassing if disclosed.

Perhaps the most significant shift is the Defense Department's bid to conduct surreptitious missions, in friendly and unfriendly states, when conventional war is a distant or unlikely prospect -- activities that have traditionally been the province of the CIA's Directorate of Operations. Senior Rumsfeld advisers said those missions are central to what they called the department's predominant role in combating terrorist threats.

The Pentagon has a vast bureaucracy devoted to gathering and analyzing intelligence, often in concert with the CIA, and news reports over more than a year have described Rumsfeld's drive for more and better human intelligence. But the creation of the espionage branch, the scope of its clandestine operations and the breadth of Rumsfeld's asserted legal authority have not been detailed publicly before. Two longtime members of the House Intelligence Committee, a Democrat and a Republican, said they knew no details before being interviewed for this article.

Pentagon officials said they established the Strategic Support Branch using "reprogrammed" funds, without explicit congressional authority or appropriation. Defense intelligence missions, they said, are subject to less stringent congressional oversight than comparable operations by the CIA. Rumsfeld's dissatisfaction with the CIA's operations directorate, and his determination to build what amounts in some respects to a rival service, follows struggles with then-CIA Director George J. Tenet over intelligence collection priorities in Afghanistan and Iraq. Pentagon officials said the CIA naturally has interests that differ from those of military commanders, but they also criticized its operations directorate as understaffed, slow-moving and risk-averse. A recurring phrase in internal Pentagon documents is the requirement for a human intelligence branch "directly responsive to tasking from SecDef," or Rumsfeld.

The new unit's performance in the field -- and its latest commander, reserve Army Col. George Waldroup -- are controversial among those involved in the closely held program. Pentagon officials acknowledged that Waldroup and many of those brought quickly into his service lack the experience and training typical of intelligence officers and special operators. In his civilian career as a federal manager, according to a Justice Department inspector general's report, Waldroup was at the center of a 1996 probe into alleged deception of Congress concerning staffing problems at Miami International Airport. Navy Vice Adm. Lowell E. Jacoby, director of the Defense Intelligence Agency, expressed "utmost confidence in Colonel Waldroup's capabilities" and said in an interview that Waldroup's unit has scored "a whole series of successes" that he could not reveal in public. He acknowledged the risks, however, of trying to expand human intelligence too fast: "It's not something you quickly constitute as a capability. It's going to take years to do."

Rumsfeld's ambitious plans rely principally on the Tampa-based U.S. Special Operations Command, or SOCOM, and on its clandestine component, the Joint Special Operations Command. Rumsfeld has designated SOCOM's leader, Army Gen. Bryan D. Brown, as the military commander in chief in the war on terrorism. He has also given Brown's subordinates new authority to pay foreign agents. The Strategic Support Branch is intended to add missing capabilities -- such as the skill to establish local spy networks and the technology for direct access to national intelligence databases -- to the military's much larger special operations squadrons. Some Pentagon officials refer to the combined units as the "secret army of Northern Virginia."

Known as "special mission units," Brown's elite forces are not acknowledged publicly. They include two squadrons of an Army unit popularly known as Delta Force, another Army squadron -- formerly code-named Gray Fox -- that specializes in close-in electronic surveillance, an Air Force human intelligence unit and the Navy unit popularly known as SEAL Team Six.

The Defense Department is planning for further growth. Among the proposals circulating are the establishment of a Pentagon-controlled espionage school, largely duplicating the CIA's Field Tradecraft Course at Camp Perry, Va., and of intelligence operations commands for every region overseas.

Rumsfeld's efforts, launched in October 2001, address two widely shared goals. One is to give combat forces, such as those fighting the insurgency in Iraq, more and better information about their immediate enemy. The other is to find new tools to penetrate and destroy the shadowy organizations, such as al Qaeda, that pose global threats to U.S. interests in conflicts with little resemblance to conventional war.

In pursuit of those aims, Rumsfeld is laying claim to greater independence of action as Congress seeks to subordinate the 15 U.S. intelligence departments and agencies -- most under Rumsfeld's control -- to the newly created and still unfilled position of national intelligence director. For months, Rumsfeld opposed the intelligence reorganization bill that created the position. He withdrew his objections late last year after House Republican leaders inserted language that he interprets as preserving much of the department's autonomy.

Lt. Gen. William G. Boykin, deputy undersecretary for intelligence, acknowledged that Rumsfeld intends to direct some missions previously undertaken by the CIA. He added that it is wrong to make "an assumption that what the secretary is trying to say is, 'Get the CIA out of this business, and we'll take it.' I don't interpret it that way at all."

"The secretary actually has more responsibility to collect intelligence for the national foreign intelligence program . . . than does the CIA director," Boykin said. "That's why you hear all this information being published about the secretary having 80 percent of the [intelligence] budget. Well, yeah, but he has 80 percent of the responsibility for collection, as well."

CIA spokeswoman Anya Guilsher said the agency would grant no interviews for this article.

Pentagon officials emphasized their intention to remain accountable to Congress, but they also asserted that defense intelligence missions are subject to fewer legal constraints than Rumsfeld's predecessors believed. That assertion involves new interpretations of Title 10 of the U.S. Code, which governs the armed services, and Title 50, which governs, among other things, foreign intelligence.

Under Title 10, for example, the Defense Department must report to Congress all "deployment orders," or formal instructions from the Joint Chiefs of Staff to position U.S. forces for combat. But guidelines issued this month by Undersecretary for Intelligence Stephen A. Cambone state that special operations forces may "conduct clandestine HUMINT operations . . . before publication" of a deployment order, rendering notification unnecessary. Pentagon lawyers also define the "war on terror" as ongoing, indefinite and global in scope. That analysis effectively discards the limitation of the defense secretary's war powers to times and places of imminent combat.

Under Title 50, all departments of the executive branch are obliged to keep Congress "fully and currently informed of all intelligence activities." The law exempts "traditional . . . military activities" and their "routine support." Advisers said Rumsfeld, after requesting a fresh legal review by the Pentagon's general counsel, interprets "traditional" and "routine" more expansively than his predecessors.

"Operations the CIA runs have one set of restrictions and oversight, and the military has another," said a Republican member of Congress with a substantial role in national security oversight, declining to speak publicly against political allies. "It sounds like there's an angle here of, 'Let's get around having any oversight by having the military do something that normally the [CIA] does, and not tell anybody.' That immediately raises all kinds of red flags for me. Why aren't they telling us?"

The enumeration by Myers of "emerging target countries" for clandestine intelligence work illustrates the breadth of the Pentagon's new concept. All those named, save Somalia, have allied themselves with the United States -- if unevenly -- against al Qaeda and its jihadist allies.

A high-ranking official with direct responsibility for the initiative, declining to speak on the record about espionage in friendly nations, said the Defense Department sometimes has to work undetected inside "a country that we're not at war with, if you will, a country that maybe has ungoverned spaces, or a country that is tacitly allowing some kind of threatening activity to go on."

Assistant Secretary of Defense Thomas O'Connell, who oversees special operations policy, said Rumsfeld has discarded the "hide-bound way of thinking" and "risk-averse mentalities" of previous Pentagon officials under every president since Gerald R. Ford.

"Many of the restrictions imposed on the Defense Department were imposed by tradition, by legislation, and by interpretations of various leaders and legal advisors," O'Connell said in a written reply to follow-up questions. "The interpretations take on the force of law and may preclude activities that are legal. In my view, many of the authorities inherent to [the Defense Department] . . . were winnowed away over the years."

After reversing the restrictions, Boykin said, Rumsfeld's next question "was, 'Okay, do I have the capability?' And the answer was, 'No you don't have the capability. . . . And then it became a matter of, 'I want to build a capability to be able to do this.' "

Known by several names since its inception as Project Icon on April 25, 2002, the Strategic Support Branch is an arm of the DIA's nine-year-old Defense Human Intelligence Service, which until now has concentrated on managing military attachés assigned openly to U.S. embassies around the world.

Rumsfeld's initiatives are not connected to previously reported negotiations between the Defense Department and the CIA over control of paramilitary operations, such as the capture of individuals or the destruction of facilities.

According to written guidelines made available to The Post, the Defense Department has decided that it will coordinate its human intelligence missions with the CIA but will not, as in the past, await consent. It also reserves the right to bypass the agency's Langley headquarters, consulting CIA officers in the field instead. The Pentagon will deem a mission "coordinated" after giving 72 hours' notice to the CIA.

Four people with firsthand knowledge said defense personnel have already begun operating under "non-official cover" overseas, using false names and nationalities. Those missions, and others contemplated in the Pentagon, skirt the line between clandestine and covert operations. Under U.S. law, "clandestine" refers to actions that are meant to be undetected, and "covert" refers to those for which the U.S. government denies its responsibility. Covert action is subject to stricter legal requirements, including a written "finding" of necessity by the president and prompt notification of senior leaders of both parties in the House and Senate.

O'Connell, asked whether the Pentagon foresees greater involvement in covert action, said "that remains to be determined." He added: "A better answer yet might be, depends upon the situation. But no one I know of is raising their hand and saying at DOD, 'We want control of covert operations.' "

One scenario in which Pentagon operatives might play a role, O'Connell said, is this: "A hostile country close to our borders suddenly changes leadership. . . . We would want to make sure the successor is not hostile."

Researcher Rob Thomason contributed to this report.