Answer:
The Marshall Plan
Step-by-step explanation:
Containment was an American government Doctrine which looked to contain the spread of Soviet influence and communist values all over the world.
As part of the global cold war, both the US and the Soviet tried to influence not only the hearts and minds of people but even sought to wage proxy wars and topple governments.
However, the most effective containment method was the Marshall Plan. An American loan to almost every European country in the Post-World War II era.
Europe was devastated by war and the loans helped to rebuild the country and turn it into an economic powerhouse. this not only opened a huge export market for the US but also created long-lasting friendly relations which culminated into the NATO alliance.