From the FAQS:

There will be many ways to advance your agent and benefit your agency within Global Agenda. This includes:

Player vs Environment Missions -- In the post-apocalyptic, 22nd-century world of Global Agenda, the Commonwealth rules the world with an iron fist. The battle against the Commonwealth unfolds in a series of player-vs-environment missions, in which you as an agent raid facilities around the world, sabotaging the Commonwealth's progress and stealing its resources. These missions can be conducted solo or you may team with others in co-op mode.

Pickup Player vs Player Missions - To earn money and hone skills outside of agency- prescribed goals, the agent may undertake mercenary activities, teaming with other elite agents and carrying out 'no questions asked' missions on behalf of NPC sponsors. These missions will involve several different map gameplay styles (attack/defend, capture-the-flag, multi-point defend, push objectives, etc).

Alliance vs Alliance Campaign -- With the Earth's population well under 1 billion, there is no shortage of available land, but a severe shortage of inhabitable land. Across much of the planet, prolonged exposure to the raw elements equals death. While geo-engineering at the planetary scale is still unfeasible, advanced technology does allow limited regions of the earth to be environmentally cleansed and protected. Thus, when a new region becomes available, independent agencies engage in a technology race to accumulate the necessary resources, facilities and personnel to control and colonize that area. This effort unfolds in our Campaign mode, in which player-formed agencies join together to form alliances that compete for territory and domination. In this type of mission, agents are working together in well-coordinated strike teams, choosing wisely whom and when to attack.