The Bush administration names CIA operatives

This is frightening. John Dean (yes, that John Dean) reports:

On July 14, in his syndicated column, Chicago Sun-Times journalist Robert Novak reported that Valerie Plame Wilson - the wife of former ambassador Joseph C. Wilson IV, and mother of three-year-old twins - was a covert CIA agent. (She had been known to her friends as an "energy analyst at a private firm.")

Time magazine published the story on July 17, and Newsday published it on July 22. Novak says that "two senior Administration officials" sought him out; Time attributes "government officials"; and Newsday notes that a "senior intelligence official" said that Wilson worked in the "Directorate of Operations [as an] undercover officer" (quotes are from the Dean article).

Why is the Bush administration naming clandestine CIA operatives to journalists? Dean argues that

The answer is clear. Former ambassador Wilson is famous, lately, for telling the truth about the Bush Administration's bogus claim that Niger uranium had gone to Saddam Hussein. And the Bush Administration is punishing Wilson by targeting his wife. It is also sending a message to others who might dare to defy it, and reveal the truth.

I'm no fan of the Bush administration, but I find it hard to believe that any administration would reveal the identity of CIA operatives for such crass political reasons. Having said that, what possible reason could there be? Given the enormous threat such leaks could pose to our ability to gather foreign intelligence, it seems to me that the House and Senate Intelligence committees ought to be asking that question. Why aren't they?