In the year 2014, the restriction of military intervention on foreign soil has been eased which fuels the need for private military companies (PMCs) to fight proxy wars for business purposes. nanotechnology has become prominent, both to enhance the capabilities and enforce the loyalty of mercenaries. The nanomachine system "Sons of the Patriots" is used commonly by the PMCs. The five largest PMCs are owned by the Outer Heaven mother company with Liquid Ocelot as the CEO. Amassing an army rivaling that of the U.S. Army, Liquid Ocelot prepares to launch an armed insurrection by taking control of the system. With the world once again in crisis, Roy Campbell deploys Old Snake to terminate Liquid Ocelot once and for all.