These shocks of 1971 marked the beginning of a new stage in relations. The basic relationship remained close, but frictions increasingly appeared as Japan's economic growth led to economic rivalry. The political issues between the two countries were essentially security-related and derived from efforts by the United States to induce Japan to contribute more to its own defense and to regional security. The economic issues tended to stem from the ever-widening United States trade and payments deficits with Japan, which began in 1965 when Japan reversed its imbalance in trade with the United States and, for the first time, achieved an export surplus.