Multi-track or two-track diplomacy was employed by the people of Portsmouth and the State of New Hampshire during the thirty days of negotiations of the Treaty of Portsmouth. In between the formal direct negotiations, the people of Portsmouth hosted informal meetings, recreational and social events throughout the local area to foster interpersonal relations between the Russian and Japanese delegations. This form of peace negotiation is becoming a new, broader approach to resolving international conflicts, especially when the parties want no formal government as an intermediary between the two. Portsmouth is a sterling example of this process before scholarship identified the name Multi-Track Diplomacy.

The term "Track Two Diplomacy" was coined in 1981 by Joseph Montville, referring to the range of unofficial contact between negotiating parties and people to enhanceand move forward the peace process. Montville, then a U.S. diplomat, used the term in contrast to Track One diplomacy, which refers to diplomatic efforts to resolve conflicts only through governmental channels.

By 1991 it became clear that conflict resolution was too complex in the modern world for two tracks to successfully negotiate an outcome of peace. This evolution of diplomacy and negotiating theory led Dr. Louise Diamond and Amb. John McDonald to coin the term "Multi-Track Diplomacy". This term was an advance on two-track theory to incorporate a number of different ways that peace could be reached through various channels.

Multi-Track Diplomacy, broadly defined refers to nine different "tracks" that all contribute to international peace and conflict resolution:

Track One: Governments

Track Two: Business

Track Three: Private citizens

Track Four: Educators

Track Five: Peace