The Inter Galactic Security Bureau does not believe that open warfare is a job for its forces. Operatives are trained primarily for quick, seek and destroy raids. We do not fly into a system and start shoot civilians, attacking all enemies in sight. We take down the targets we need to in order to achieve our main objective and get out.
At the same time, we firmly believe our RP should not expressly prohibit drawn out fighting as, sometimes, we're the only ones in a position to fight off an attack. We simply go as far as we need to. The role of the navy is to stop the houses of Sirius from being invaded, whereas ours is more to stop any internal threats to the security of the state.