When we had a nuclear missle crisis with Cuba, Cuba's allies was on edge because they thought the U.S was about to start a war but it was an accedient. With that Cuba and the U.S relations were in hot water so since then Cuba has been on edge ever since.
So to answer your question, the nuclear missiles showed massive threats and were prepared for the worse thing posaible ...war.
Hope this helped :)
Have a great day
