One organization that can serve as a model for an international satyagraha force is the Christian Peacemaker Teams.
CPT uses the tactic of sending international teams to help repressed peoples resist nonviolently. They accompany the people and act as witnesses and deterrents to acts of violence by the military or paramilitaries.
CPT has sent teams to Iraq, Haiti, Chiapas in Mexico, Colombia, and Palestine.
The main denominations supporting CPT are Mennonites, Church of the Brethren, and Friends. It also partners with other Christian peace groups, with Jewish and Moslem peace organizations, and with secular groups such as International Solidarity Movement and Peace Brigades International. Wikipedia has a good article on CPT.