
The Helghan Corporation sought to buy ownership of Vekta as well, but when the UCN imposed sanctions against its unfair business practices, a war broke out (known as the First Extrasolar War), which led to the ISA, the military arm of the UCN, driving the company out of Vekta. Partnering with private firms, the UCN moved to establish human colonies in Alpha Centauri, a system occupied by two planets: Vekta, a rich Earth-like world (named after the CEO of the mining conglomerate Helghan, Philip Vekta), and Helghan, a barren wasteland named after the same company. After nuclear war rendered much of the Earth uninhabitable in 2055, world governments formed an international order known as the United Colonial Nations. Killzone is set in an era of space colonization set in the year 2357. Can you survive the Helghast assault and halt the march towards all-out war, or will you be just another faceless casualty in unmarked grave?" ―Game description As a skilled member of an ISA squad, you find yourself in the middle of the desperate conflict. The peaceful colony of Vekta becomes the first victim of Helghan's retribution, quickly falling under enemy control in a bloody blitzkrieg that leaves thousands dead or injured. The ruthless, militaristic Helghast secede from the ISA, conspiring to wage war against them. Those that survive become stronger, and develop a burning hatred for the alliance that sent them to the accursed planet in the first place.

On the planet Helghan, colonists find themselves warped by the poisonous atmosphere. But behind the smiling façade of galactic growth, unrest is growing. New colonies are formed under the Earth-loyal banner of the Interplanetary Strategic Alliance. " In the near future, mankind takes to the stars and begins a halcyon period of planetary colonization.
