Was the decision to stay out of the war until 1941 a wise one on the part of the United States?

Given that the Japanese aggression began in 1931 with the invasion of Manchuria and given that the German aggression began in Europe in 1936, why was it not until 1941 that the United States joined the war against the Axis nations? Was the decision to stay out of the war until 1941 a wise one on the part of the United States?