Why commit suicide and not just...?
.... kill Commander Farrell?
Towards the end of the movie, Pritchard has just developped his theory of Farrell being (a) Susan's lover, (b) Susan's assassin and (c) Yuri, next thing Farrell is threatening to expose the whole handling, or even worse take up on Bryce's conspiracy proposition against Pritchard,
so why not kill Farrell on the spot? This would be justified afterwards as an act of self-defence -if not an act of patriotism- since there were no other witnesses in that room. Moreover Pritchard seems like a ruthless man, he just killed the computer guy for much less reason. On top of it, Bryce looks like a man easily convinced by his counsel, it is pretty sure that in the next 30 seconds Pritchard would have persuaded his boss that the turn of the situation was at his best interest.
I am a great fan of NO WAY OUT, it is my favourite 80's film, I like the ending, I have watched the film times and times again, but from the first time, I can't help asking why this resourceful man came up with such a panic decision while he seemed on top of the situation since the beginning.
To me, this is the only hole in the movie's amazing plot.