The policy contributed most to the nuclear arms race was Mutual Assured Destruction
This means that both sides knew that any attack upon the other would be devastating to themselves, therefore restraining them from attacking the other. Each side possesses enough nuclear weapons to obliterate the other side that causes them to restrain from attacking afraid of the annihilation.
The railroad was able to aid others in communication, transportation, and products. An example is mail. People used trains to transport mail in order to communicate with others. Traveling was also cheaper and safer now with railroads since it was able to get people where they needed to be much more quickly. And finally products, manufacturers could send supplies to other places in a short amount of time much more easily.
Hope this helped
To declare war. HOPE IT HELPS
