Why was the Test Ban Treaty signed?

• It raised fewer difficulties beacsue it dealt with one small part of the nuclear issue not the whole disarmament problem
• Both the Soviet and Western governments wanted to resppond to public opinion which had been concerned about the environmental effects of nuclear test since 1954 , when the crew of the Japanese fishing boat "Lucky Dragon" had been badly affected by fall-out after a test in the Pacific
• US president Kennedy and Khrushchev were anxious to build on improved East-West relations following the 1962 Cuban missile crisis