What moral question was at the heart of the arms race?

People have agreed the "Cold War" came to an "end", and with it so the end of "The Nuclear Arms Race" (U.R.S.S & U.S.A competing for nuclear supremacy), all atributed to the colapse of the U.R.S.S.; a period of worldwide tension in mankind's modern history, due the principle of "Mutually Assured Destruction" that indeed involves weapons of massive destruction, where the strike of one side triggers the other side's attack and everyone inside would be terminated (meaning the whole world) accordingly; thereby the question was definitely:

Does it worth ending human civilization because of a pride argument?

Explanation:

d. migration of french settlers into english colonies

the use of email to replace slower surface mail.