It's an excellent flick with a tremendous performance by one of the greatest actors of all time, Al Pacino. Not to take anything away from Chris O'Donnell who was also very good as Charlie.
I saw it a long time ago when I wasn't suicidal so the I guess I felt Charlie changing Lt Col. Frank Slade's (Pacino) decision to kill himself uplifting. From my suicidal perspective today, I applaud Frank Slade's decision to spend all his money on one last trip to NYC and blow his brains out in a luxury hotel while wearing his military uniform. It's Hollywood so of course Charlie has to intervene to change the Lt Col.'s mind.
The suicide prevention was the less important part of the movie, although it enabled the Lt Col to save Charlie from expulsion at Baird. The most important part was how the Lt Col saved Charlie's integrity and let him stay at school.
I guess you could say they both saved each other's lives.