In 1968 my high school history teacher asked the question: "What would you do if you were President and the USSR launched a massive nuclear strike on the US?" The liberals in the class, including me, all said we would not fire back because the massive exchange would certainly kill all humans on earth. The right-wingers all said they would nuke the Sovs off the face of the planet. Fascinatingly, there was no "in between".
As for "Fail-Safe", it optimistically assumes everybody concerned is extremely even-tempered, calm, and reasonable---I doubt if anybody would be so reasonable in a real situation of this nature. The film is a wonderful expression of mid-'60s liberal idealism.
By the way, the Walter Matthau character was supposed to have been based on both Henry Kissinger and Edward Teller.
I assume your question is would you have bombed New York to stave off all out Nuclear War or simply fire off the rest and pray you win or "lose less". I've always loved this film and understand completely the paradox. I think that a great many people acted irrationally and emotionally during the film. I don't think everyone was calm at all.
To your question. I believe Fonda's choice was the ONLY one to make. You trade devastated cities and hope you've learned from your mistake.
Saw this movie on its release just after my 10th birthday. Dad took me. I remember being disturbed by it. For my entire life, well ten years of it anyway, I believed that the USA was infallible. The many, many WWII flicks with John Wayne, Aldo Ray, Audie Murphy, et al, had conditioned me well. This film shook me like nothing before. Heck, even the Cuban missile crisis was relatively unimportant to me when it was happening, in that I couldn't grasp the seriousness of the moment. This film drove it home. It haunted me for a bit. But being 10 years old the film eventually slipped from my mind and I continued to be the boy that I was.
I have not thought about that film in years. But obviously it had an impact.
I found this piece on Wiki about a theoretical World War III, the artical has a section in it detailing how close we have come to nuclear war. It is frightening to see that there are two incidents where a "launch" was detected which later turned out to be malfunctioning equipment. http://en.wikipedia.org/wiki/World_War_III
Long as I remember The rain been comin' down. Clouds of myst'ry pourin' Confusion on the ground. Good men through the ages, Tryin' to find the sun; And I wonder, Still I wonder, Who'll stop the rain.
It's a great film as are most all Henry Fonda movies. A very believable actor in almost any role.
I do think far more even tempered men were running the world at the time this movie was made. I'm sure both the USSR and Red China would have love to obliterate the U.S. At the same time they were obviously sane enough to realize it was a no win situation for all concerned. A very direct contrast to the world we live in today.
Laugh more often and love harder. Your life will seem easier.