The United Nations of Earth (UNE) were obliged to sign the Sirius Treaty in the late 23rd century after a furious war between the star-faring species in the universe. Now supposedly the Sirius Treaty enforces a peace in which a cold war seethes between those same species.
Under the watchful eye of the enforcers of the treaty, the harsh Invigilators, these same treaty species continue their search for resources and ancient artefacts on primitive planets. And the soldiers of the UNE's Sirius Treaty Special Forces venture forth onto those primitive planets armed with the best swords, spears and armour the UNE can buy. They are on their own, unable to call on any of their technology for help, totally reliant on primitive equipment - and their own, personal, upgrades to body and mind.