WITH A STORY as enticing, complex, competitive and quickly unfolding as Watergate, there was little tendency or time to consider the motive of our sources. What was important was whether the information checked out and whether it was true.

There was no time to ask our sources: why are you talking? Do you have an axe to grind? Why don’t you blow the whistle publicly, and tell all you know? This was the case with Mark Felt. I was thankful for any information, confirmation or assistance he gave me while Carl (Bernstein) and I were attempting to understand the many-headed monster of Watergate. Because of his position as No 2 at the FBI, his words and guidance had immense, at times even staggering, authority. The weight, authenticity and his restraint were more important than his design, if he had one.

It was only after President Nixon resigned that I began to swim up that stream seriously. Why had Felt talked when it carried substantial risks for himself and for the FBI? Had he been exposed early on, Felt would have been no hero. Technically, it was illegal to talk about grand jury information or FBI files; or it could have been made to look illegal. In retrospect, Felt had believed that he was protecting the bureau by finding a way, clandestine as it was, to push information from the FBI interviews and files out to the public, to help to build public and political pressure to make the President and his men answerable. The FBI findings that Watergate had many tentacles had been ignored and buried.

In the autumn of 1972, as we were writing critical Watergate stories, Carl and I had signed a book contract with Simon & Schuster. We decided we had no alternative but to write the story of covering Watergate as Washington Post reporters. It was what we knew best.

Times Archive, 1974: Backroom boys of Watergate

Bernstein and Woodward identify their main source as 'Deep Throat', who prosecutors believe was Mark Felt Jr, a deputy associate director of the FBI

• Guessing the identity of 'Deep Throat', 1976

• Archive Topic: Watergate and the Fall of Nixon

Related Links

• Watergate mole's motives questioned

• Watergate 'Deep Throat' dies

I called Felt and asked, gingerly, that since he was now retired, and since he had let me quote him on the record defending the FBI, would he let me identify him for the book? He exploded. Absolutely not. Was I mad? It was about as emphatic a “no” as anyone could receive. Angry and unhappy, he told me: don’t call here again. Our agreement was that there would be no identification of him, his agency, or even a suggestion in print that such a source existed.

Felt made me feel shame. I wondered how I could have made such a request. Certainly he had made representations to his colleagues at the FBI, the club, and to his friends and family that he had not been a Watergate source for us. Exposure would challenge his probity with everyone important in his life. He still had potential legal liability. But most important, Nixon was still President. The Watergate cover-up was continuing and Nixon still seemed determined to plug leaks. Felt ’s contribution had been sufficiently under the radar that no one other than Carl, me, a few other reporters vaguely and the Post editors, even knew there was a secret high-level source who was underpinning some of our stories.

I vividly recall phoning Felt after the book was released. I was dying to know what he thought. When he heard my voice, he hung up. For days I was haunted, imagining the worst. That ranged from the possibility that he might take his own life to the likelihood that he would go public and denounce me as a betrayer who had exploited our accidental friendship. Or he might claim that I had described our relationship or some information inaccurately. After all, only he and I knew. I can still hear the bang of his telephone and the sudden dial tone. Hanging up was worse than any words he might have uttered. I wanted to know what he was thinking, but I did not have the courage to call him again. What was the storm he was living? How much was directed at me? What I didn’t know then was that Felt was in big legal trouble and he needed to preserve his law enforcement ties. J. Edgar Hoover, for the six years before his death in May 1972, had prohibited the use of the so-called black-bag jobs, covert break-ins, to gather intelligence in domestic security cases. That changed with the rise of the Weather Underground Organisation (WUO). There was some evidence that the WUO had connections with foreign governments, and the group had taken responsibility for the 1971 bombing of the Capitol and the 1972 bombing of the Pentagon. On July 18, 1972, Pat Gray, head of the FBI, had written to Felt, saying of the WUO: “Hunt to exhaustion. No holds barred.”

Felt and Edward S. Miller, the head of FBI intelligence, decided to authorise break-ins by special FBI teams. Clandestine entries into the homes or offices of relatives and friends of WUO fugitives seemed a good way to develop leads for locating them. On at least five occasions, Felt approved black-bag jobs without consulting Gray.

On April 10, 1978, a Federal grand jury indicted Pat Gray, Felt and Miller, now no longer head of FBI intelligence, charging that they did “unlawfully, wilfully and knowingly combine, conspire, confederate and agree together and with each other to injure and oppress citizens of the US who were relatives and acquaintances of the Weathermen fugitives”.

It was a front page story in the Post. Sometime afterward, I reached Felt by phone. He sounded worn, tired. There was a hesitation in his voice, that of a man facing jail, probably the last place he thought he would wind up. The felony indictment meant that if convicted he could be punished with a prison sentence of up to ten years or a $10,000 fine or both.

I said I was truly sorry that it had come to this. He sounded, or acted, as if he did not recognise my name or my voice, as if I were some stranger or caller voicing sympathy. “Thank you,” he said with a dry edge to his voice.

I tried to break through, saying something like: “Bob Woodward, you know, from The Washington Post?” I believe he groaned.

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