After a great season one they just gave up? The end where they tried to kill POTUS and everyone important at the hospital was pretty similar to the Super Bowl and all the cabinet officials at it getting bombed in Sum of All Fears, but it was otherwise good.

Half of season 2 was repeating Clear and Present Danger's plot of getting the black ops team out of the jungle and killing those running the camp and the other half was dogcrap.

Half of season 3 was a repeat of Red October's plot of Ryan averting WW3 by convincing a Navy commander a Russian ship ready to attack shouldn't be fired upon. Not as bad as season 2, but still needlessly convoluted.

Season 4 is based on Clear and Present Danger (again) with a promoted Ryan inheriting a program that was shut down and trying to uncover the corruption and not to get killed by those left out to dry. They couldn't even resist involving a drug cartel.

Rarely is so much potential wasted.