Julianna Margulies forms an interagency (National Security Council, FBI, CIA, MI5, and MI6) task force after a sarin attack in London in this mini-series.
Dylan McDermott also stars. (At first I thought he was David Schwimmer.)
Does anyone remember this one? I've just started watching the DVDs and so far, so good.

[was Homegirl] Love to be home . . . thus the screen name. Joined 2003.