Your link, the Kristof article, says Ames outed her before his arrest in '94. Then says she was compromised and brought home. But doesn't say when. At all. Presumably, just sometime after Ames was caught and the extent of his treason became known.
Ya got anything saying she was recalled in '94?
Even if Plame was in Europe when you suggest (and I don't see any proof to substantiate your contention) so what? That wouldn't in and of itself prove she was under cover. I lived in the DC area for years and knew many CIA and NSA employees, many of whom were abroad in various assignments, but they worked as bureaucratic stiffs, not undercover. Although I suspect Plame's main attraction to the CIA was "under the cover" if you get my drift.
In 1997, Plame moved back to the Washington area, partly because (as was recently reported in The New York Times) the C.I.A. suspected that her name may have been on a list given to the Russians by the double agent Aldrich Ames in 1994.
I gave you a link that said they brought her home in 1994.
Now where is YOUR proof that she was still in Brussels UNDERCOVER in 1997?
Matt Cooper? What are you doing on FR?