Following WW1, which was considered by most Americans as a futile war of little importance to the US, the US entered a consensus (majority agreement) that they should adopt a policy of "isolation" towards Europe, which was increasingly unstable. The US public did not want to be drawn into another European war. Although, the US mantained strong economic links, such as the various economic bailouts and loans they gave to Germany's Weimer Republic and exported greatly to Europe.
Basically your answer is a Policy of Isolation.
Hope I helped :)