Third Party Non-violent Intervention
Third Party Non-violent Intervention (sometimes called TPNI) refers to the practice of intervening from the outside in violent conflicts to attempt to reduce violence and allow "space" for conflict resolution. Two common forms of intervention are as an intermediary in a negotiating capacity or, physically, by interposing one's body between two factions.
Source: Wikipedia — Third Party Non-violent Intervention (CC BY-SA 4.0)