This movie serves as a sharp reminder of how paramount it is to the success of a film to have decent writers on board. I know it may sound like an utterly trite, common-sense lesson, but the fact that this movie turned out the way it did shows that there are people out there in Hollywood who have not yet learned. This movie had a really solid cast, a big budget, and an exciting premise. And yet, from beginning to end, viewers are served up forgettable characters with poorly-developed back-stories, going through the motions in a plot that never hooks their interest. I watched the whole movie and could care less about Michael Douglas's fugitive character. This one does not measure up to the level of The Fugitive (1993). It is definitely more on par with say, U.S. Marshals (1998).
In fact, the only thing about this film that is worthy of discussion is which of its many facets was the most one-dimensional? There is a serious competition going on between: the main-character's relationship with the first lady, his feud with Keifer Sutherland's character, the secret plot to kill the President, the rookie agent played by Eva Longoria, and finally the question of which member of the Secret Service is a mole.
The film's climax and subsequent resolution one finds boring, banal answers to all of those questions that they never really cared much about to begin with. The overall impact on the viewer was virtually non-existent. This movie was lighter than air.
Overall, I think a 3 stars' is reasonable mark: the movie could have gone straight to the TV (as some other users say). There's not so much difference between this film and the ones you might see at home. `The Sentinel' is a forgettable thriller and there is absolutely no reason to recommend it.