The Green Brigade is an environmentalist terrorist group seen in the EndWar novel that were being supplied by the Russians. The Forgotten Army is a splinter group of the Green Brigade.

In Green Brigade uniforms, the Russians hijacked a satellite and destroyed the Freedom IV, the spacecraft carrying the final piece of the Freedom Star, a controversial orbital platform that the United States (US) was constructing to deploy U.S Marines in any war situation. The Green Brigade planted the nuclear weapons for Operation: 2659. That plot was stymied by the U.S. NEST teams.

The book also makes references to a base in Bulgaria where there was a Green Brigade training camp, possibly meaning that the Green Brigade is a European group. The Green Brigade is led by the Green Vox.