20世纪70年代以后,美、俄、法等国开始研制发展第三代和第四代核武器,其中第三代核武器,已有多种型号研制成功并装备部队,第四代核武器尚处于研制之中。 Since the 1970s, the United States, Russia, France and other countries started to develop and develop the third and fourth generations of nuclear weapons. The third generation of nuclear weapons has been successfully developed and equipped with various models and the fourth generation of nuclear weapons is still under development in.