Original: However , following the overthrow of the Indonesian regime led by President Sukarno , in a telegram dated 19 September 1966 , Indonesia notified the Secretary-General of its decision '' to resume full cooperation with the United Nations and to resume participation in its activities starting with the twenty-first session of the General Assembly '' .
Simplified: On 19 September 1966 , decided '' to resume full cooperation with the United Nations and to resume participation ( start joining ) in its activities '' .