Unrealistic drama
I enjoyed this film, particularly because you get a chance to see a cast of budding future stars, and for the somewhat pro-military theme that was fairly novel at the time (America was still suffering a major Vietnam hangover, and the film clearly is sympathetic to young military men who are feeling the sting of downsizing from know-nothing bureaucrats who probably were responding to the mood of the country at the time).
However, there is one glaring flaw with the plot. In any such situation, with a bunch of teenagers -- albeit with weapons -- who are, (1) Not holding any "civilian" hostages, (2) Not explicitly threatening anyone with violence, (3) Making very reasonable demands to simply talk with a board of trustees, it is entirely unrealistic that the governor of the state would order military action that would likely result in a great number of casualties. Remember, these are young men who before the takeover were models of law-abiding citizenry, responsibility, discipline, and achievement. This wasn't a situation like inmates taking control of Attica. I found it absurd that the military, just before Moreland decided to give up, was prepared to storm the gates and start blasting the place to Kingdom Come with machine guns, tanks, and helicopter aerial assaults.
This didn't ruin the film for me, but it was bothersome. In the real world, negotiators would probably have promised the students something or other, gotten them out of there, and reneged on any promises later.