Tuhia he tomokanga mo tenei whitianga - I te timatanga o te tau 1948, i mahi a Henkin i te tari o te United Nations o te United States Department of State, i reira ia tetahi o nga tangata e whai mana ana mo te Convention Relating to the Status of Refugees i te 1951, he kirimana i whakatauhia te tautuhinga i whakaaetia e te ao mo te mea he rerenga, me te whakatakoto i nga whakaritenga mo nga whenua ki te whakarato i te whakarurutanga ki nga tangata kua tohua. I mahue ia i te tari State i te tau 1956 ki te whakaako mo te tau i te Whare Wananga o Columbia mo te kaupapa o te whakakorenga karihi i waiho hei kaupapa mo tana pukapuka 1958 "Arms Control and Inspection in American Law". I whakaako ia i te Whare Wānanga o Pennsylvania mai i te tau 1958, e haere tonu ana i tana mahi i whakaputaina hei "The Berlin Crisis
me te United Nations" i te tau 1959 me te pukapuka "Disarmament: The Lawyer's Interests", i tukuna i te tau 1964.