The US policy of containment affected Europe economically because it led the US to tie Western Europe more closely to itself. Containment was the desire to keep communism from spreading into Western Europe. One way to do this was to help keep the economies of these countries prosperous and to tie them to the US. The US did this through such things as the Marshall Plan and through the creation of the Bretton Woods system that would set up basic rules for how the major free countries would relate to one another economically. As the US did these things, it helped the countries of Europe to become richer. It also helped tie them together (and to the US) more strongly.