Always remember that expansion is achieved by diplomacy, not by the military. Starfleet's mission is to preserve the peace; our ships are not intended to start wars, but to end them. We attack only as a last resort.
The United Federation of Planets, often abbreviated UFP, is a political organisation within the Star Trek fictional universe, and almost all Star Trek video games have their story told from the perspective of this organisation. Their military arm is known as Starfleet, and many video games focus on a specific Starfleet vessel.