A 30-year-old mystery that has captivated generations was finally solved this week when the legendary Watergate informant nicknamed Deep Throat was identified.

Former FBI second-in-command W. Mark Felt, now 91, disclosed his identity to his attorney for an article that will appear in Vanity Fair magazine. The Washington Post, the newspaper that used the anonymous source to help tell the story of Watergate that ultimately led to the resignation of President Richard M. Nixon, confirmed Felt's claim.

Americans far and wide should admire Post reporters Bob Woodward and Carl Bernstein for paving the way for today's investigative journalists.

Where some people saw just a simple burglary at Democratic Party offices at the Watergate building in Washington during Nixon's 1972 reelection campaign, the reporters, with the help of Deep Throat and other anonymous sources, saw much more.

Investigations eventually revealed covert Nixon administration spying on and retaliating against a host of perceived enemies and the president's own role in trying to cover-up his administration's involvement.

Nixon, facing almost-certain impeachment for helping to cover up the break-in, resigned in August 1974. Forty government officials and members of Nixon's reelection committee were convicted on felony charges.

It would not have been possible with Deep Throat, who urged Woodward and Bernstein to follow the money trail, and the Post's willingness to use unnamed sources. After the recent Koran abuse scandal, many people have questioned the value of unnamed sources but the Watergate story shows two things:

that Woodward and Bernstein had a legitimate source as they claimed and that the methods used were justified.

The scandal led Congress to overhaul the nation's campaign finance rules, ordering federal candidates and national party committees to disclose their donors' identities and observe new contribution limits.

Amazingly, the secret withstood 30 years of speculation and investigation.

America now knows the "who" but still does not know the "why" of the case. Why did Felt reveal this information to the reporters, why did he "betray" the nation, as some have said.

The Post speculates that it may have been politically motivated since Felt was passed up by Nixon to be the FBI chief.

Whatever the reason, Felt should be remembered as someone who helped the nation see its highest leader in a new light. And the value of that is no mystery at all.