Sean Gilman’s review published on Letterboxd :
I'm not exactly sure why I disliked this so much 13 years ago, but I suspect it had to do with failure to meet expectations. "The first half of the film isn't anything like Hard-Boiled therefore this movie sucks." That kind of silliness.
Anyway, the first half of the film isn't anything like Hard-Boiled, instead it's a mishmash of Hitchcock (To Catch a Thief, North by Northwest, Notorious) with Thandie Newton dominating the screen. It loses something in the second half when, after the committing the most heroic act in the film, Newton disappears from the action in favor of non-stop Woovian action sequences.
This is perhaps the least verbal Tom Cruise performance I've seen. His Ethan Hunt here is stripped of pretty much all of the star's charm and baggage, leaving a pure instrument of violence. The first film gave him a team to avenge, the third a wife to rescue. Here he's a man doing his job, with a slight nod to psychology borrowed from Hitchcock, referenced but not emphasized.
Woo further explores his Scooby-Doo fantasies with some nifty face mask pulling (three times in the film, in the beginning, middle and end), and of course the hilarious intrusion of a flock of seagulls into a climactic action sequence. Woo at his best is always uncomfortably close to self-parody, and so is always an easy mark for those who don't want to take him seriously. But the final scenes here, as Cruise and Newton are wordlessly reunited, are among his most poignant.