What is the name for the following idea? if one country becomes communist, one by one, the others will also become communist until the entire region is under communist control.

a) the domino theory
b)the infection of communism
c)the containment strategy

A.
 Because the domino theory says if one country in a region came under the influence of communism, then the surrounding countries would follow in a domino effect.

To have a bunch of countries to team up, and communicate not let the communist break them apart and take over the world

Britain and its empire stood alone against hitler and mussolini. in june 1941, hitler broke the non-aggression agreement with stalin and germany invaded the soviet union. in december, japan attacked the us and britain. the main lines of world war ii had formed.