Act of Aggression is a real-time strategy game developed by Eugen Systems and published by Focus Home Interactive. In the year 2019, the "Shanghai Crash" triggered the eventual collapse of the entire Chinese financial system. It plunged the whole world into an economic recession, the largest since the Great Depression. Third world countries suffered the worst from the crisis and were on the brink of collapse. "The Cartel", a Private Military Corporation, seizing the opportunity to become a dominant superpower as a military-industrial global syndicate, covertly infiltrates most of the weakened countries and establishes them as the Cartel's puppet regimes.

Feeling is that the Shanghai Crash was not the result of a business rundown, but was orchestrated by an unknown group of individuals. Initial investigations into this theory ceased, due to lack of evidence, and the theory is now dismissed as a conspiracy theory. The United Nations, determined to investigate and uncover the truth behind the Shanghai Crash, has signed the "Chimera Protocol" in secrecy. This protocol binds several UN Members states together to provide military intelligence and support for further investigation. With several black ops operations executed the UN slowly uncovers evidence.

The United States, suffering from the economic crisis and recurring defense budget cuts, struggles to maintain its influence as a global superpower. Around 2025, as relations with a newly formed Mexican nation, close to the American borders, deteriorate, American Forces intervene, resulting in a conflict that may drag in the two other factions.

• Act of Aggression