Clear and Present Danger, with Harrison Ford starring as CIA agent Jack Ryan, delivers what it promises (which wasn't much). The plot is isomorphic to the Iran Contra affair. The President of the United States, after the murder of one of his friends by a member of the Colombian drug cartel, decides that the death must be avenged and authorises a covert mission to fight a private war against the drug cartel. The mission is carried out by another agent of the CIA, who is not as scrupulous as the highly moralistic Jack Ryan (very rare in DC these days).
Things go awry when the President and the Director of the CIA both decide that the mission must be aborted and callously sever all ties with the operatives on the mission in Colombia. Ryan then learns of this and goes down to help the operatives out. He succeeds not only in doing this, but also in finishing off the entire cartel. He then testifies in front of Congress about the two-facedness of the President and the others involved in this cover-up.
The novel is the first Tom Clancy book I read (I then proceeded to assimilate the others) and I found it below the quality of the Hunt for Red October or Patriot Games. The same could be said for the movie. The performances are not the greatest (especially during the beginning---it improves as things move along) and some of it is a bit hard to swallow. In order to get in the entire plot, there is some sacrifice made in terms of the action scenes (for a person holding a paper-pushing job, Ryan can sure fight well). I was a bit skeptical about the President having so much power (authorising something without Congress approval), but John corrected me about this and pointed to the Iran Contra business. In those terms, it is good to keep this in mind given that Ollie North is running for Senate.
Everything was rushed and there wasn't much time given for any of the characters to develop (the case of the Director's secretary being killed just to provide a plot line is an example). This could be the reason one reviewer commented that the memories of the movie would have faded by the time you reach the parking lot. Still, it's worth watching on the big screen if you can afford it and don't have much choice.