In some Western European countries, for example France and Italy, the desperate economic circumstances after World War Two meant support for communist parties was strong, and there was a possibility that they could win democratic elections.
The USA did not want this to happen.
In 1947, President Truman sent General George Marshall to see what could be done to reduce popular support for communism. There was immediate concern for Greece and Turkey.
Truman gave $400 million dollars to the two countries and in return established missile bases in Turkey.
Marshall recommended spending a lot of money - over $12 billion to be exact.
This Marshall Aid would be spent to help the economies of Western Europe recover after World War Two and make them less likely to be won over by communism.
The money was to be offered to all the countries of Europe, not just the West, but Stalin prohibited the countries in his sphere of influence from taking it.
The USSR objected to Marshall Aid in several ways.
In all, sixteen countries received Marshall Aid, Britain and France being the major recipients. West Germany also received just under $1.4 billion.
Stalin was very angry with this, he did not want a strong Germany; in the East, he deliberately weakened the Soviet occupied zone in Germany.
In the West, Truman wanted to create a powerful buffer against communism. He did not want Germany to be weak.
By 1952, most Western European countries had recovered to their pre-war levels of production. The communist parties in France and Italy lost their support as standards of living rose.
Marshall Aid had been very effective in preventing the spread of communism in Western Europe and had created economically strong democratic allies for the USA.
However, it clearly put a strain on relations between the USSR and the USA and its allies.
Marshall Aid was effectively a propaganda tool, aimed at convincing countries they would be prosperous with American capitalist support.