Answer:
to form a bloc of western nations to defend against Soviet aggression
Step-by-step explanation:
As a result of the increase and influence in the expansion of communism style of government and ideologies spreading the Soviet Union.
The United States along with some other Western European countries decided to form the North Atlantic Treaty Organization (NATO), formed in 1949.
The original purpose behind this group formation is to "form a bloc of western nations to defend against Soviet aggression."