In May, 1974, the Indian Government detonated a "peaceful nuclear explosion." The device contained heavy water supplied by the United States and plutonium that had been reprocessed from the spent fuel of a research reactor supplied by Canada. That event shocked the governments involved in international nuclear commerce into greater efforts to prevent the diversion of civil nuclear assistance to military purposes. By 1976, France and West Germany had joined the United States in pledging not to export facilities for the production of plutonium. Two years later the major suppliers agreed upon guidelines intended to ensure that international safeguards would be applied to all sensitive nuclear exports.