The Korean War turned the Cold War into a global issue rather than a European one and worsened tensions between the East and West. Russia flooded aid into China and consequently, the two Communist giants became less trusted and more feared.
America was very committed to a theory called the "Domino Theory" and the Truman doctrine of containment. America believed that Communism was likely to spread very rapidly if left, and if just one country fell to it then many others would follow, just like a game of dominos. This feeling was present during all of the U.S. presidencies.
When Lyndon Johnson became President, he was a very firm believer of the Domino theory and had a complete hatred of Communism. …