John Washburn has been a Foreign Service Officer and a senior United Nations official. He is a fourth generation Unitarian-Universalist and represented the movement at the 1995 founding meeting of the international NGO Coalition for the International Criminal Court. In the same capacity, he participated in the United Nations negotiations to create the Court and in their final conference which adopted its Rome Statute in 1998.

He was the convener of the American NGO Coalition for the International Criminal Court throughout 2001 – 2019. He convenes the Washington Working Group on the ICC. He is also a consultant and volunteer for the Unitarian Universalist United Nations Office and through it continues to represent the movement in the international Coalition.