WASHINGTON -- When Gen. Michael Hayden took over as director of the National Security Agency in 1999, he faced a huge organization that was overwhelmingly staffed by aging white men who had spent their careers specializing in the intricacies of the Soviet Union and other aspects of the Cold War. He set out to overhaul the signals collection service and move it into the 21st century.

He came out of that anti-Soviet mold: When attached to the U.S. Embassy in Bulgaria in the mid-1980s, he would dress in workingman's clothes, ride trains and, with his cap pulled over his eyes, pretend to doze while eavesdropping on Bulgarian soldiers heading home on leave. Yet, Gen. Hayden managed to reinvent himself, and has gone on to thrive in the post-Sept. 11 world, even though he hardly would be considered an expert in terrorism or the Middle East, the two major problems on which today's Central Intelligence Agency is focused.

Despite his military background, Gen. Hayden, 61, who grew up in Pittsburgh, is something of a nonconformist. There is a pattern in his career of independent thinking, probably one reason he was able to thrive in the current security environment.

During the mid-1990s, when he was an Air Force colonel overseeing intelligence at the U.S. European Command, Gen. Hayden was outspoken in arguing that U.S. policy in the Balkans was too pro-Bosnian and insufficiently understanding of the Serbs' plight.

If Gen. Hayden is nominated and confirmed as director of the CIA, succeeding Porter Goss, whose resignation President Bush accepted Friday, he'll be taking over an institution that has been battered in recent years and even treated at times by the Bush administration as an adversary. Agency insiders likely will be suspicious of him as an outsider, a career military man. They also will be skeptical that the mild-mannered Gen. Hayden can protect them from the bureaucratic maneuverings of Defense Secretary Donald Rumsfeld, who in recent years has built up military intelligence and made it more independent of CIA oversight.

Even getting confirmed could be tough, especially on the eve of a mid-term election in which Democrats will be seeking to regain control of Congress. Gen. Hayden has long worked at developing good relationships with members of Congress, but those ties have frayed lately, mainly because of the NSA's domestic surveillance program.

On Dec. 17, 2005, when the existence of that program was revealed in the New York Times and the Washington Post, Rep. Jane Harman, D-Calif., the vice chairman of the House intelligence panel, called Gen. Hayden on her cellular telephone. The general was on a family outing in Annapolis but told Rep. Harman he would drive back to Washington to brief her and intelligence panel colleagues on the program. He promised to be there in two hours. Harman began organizing for a briefing but within the hour Gen. Hayden called and canceled. "The White House yanked his permission to do so," Rep. Harman said in an interview.

For members who had grown used to his availability, candor and nonpartisan approach, the turnaround came as a shock. "It certainly made some of us wonder whether he's the independent person we thought he was," said another member of Congress.

If confirmed, the next hurdle Gen. Hayden would face would be running and re-energizing the CIA. A senior intelligence official said, along with several others, it would be a mistake to put someone in uniform in charge of a civilian agency. Officials close to Gen. Hayden suggested that the four-star general may retire from the military.

A major test will be how he handles Rumsfeld. In their views of the nature of contemporary war, the two men are aligned. But in recent years Gen. Hayden has clashed with the defense secretary over organizational and bureaucratic issues.

Gen. Hayden grew up on the North Side with his brother, Harry, sister, Debby, and parents Harry and Sadie. Pittsburgh Steelers owner Dan Rooney was his football coach at St. Peter grade school, now called Cardinal Wright Regional Elementary.

After graduating from North Catholic High School, he attended Duquesne University, earning a bachelor's in history in 1967 and a master's in American history in 1969. He married his wife, Jeanine, also a Dusquesne alum, while in graduate school.

Years later, they told professor Steven Vardy that they met during his introductory course on Western civilization. Then, Gen. Hayden "actually walked from the North Side to the campus because he didn't have much money," Dr. Vardy said.

The professor and his former student reconnected about a decade ago when Gen. Hayden returned to his alma mater to give a talk. The professor asked to be called by his first name, as he had long called the general Mike.

But the next E-mail he got from the man he described as "a hard worker" and "down-to-earth" once again started, "Dear Professor Vardy."

Gen. Hayden was in Pittsburgh in March to attend an Duquesne alumni luncheon. His widower father and brother still are in the area, and his sister lives near Steubenville, Ohio.