Knife Edge — Christopher G. Nuttall

An all-new story of The Empire's Corps! Earth has fallen.  The Core Worlds have collapsed into chaos.  War is breaking out everywhere as planetary governments declare independence, entire sectors slip out of contact and warlords battle for power.  The remnants of the once-great Empire are tearing themselves apart.  And, in the shadows, the Terran Marine Corps works to save what little they can to preserve civilisation and build a better tomorrow.  But now they might have met their match. The marines have seized control of the corporate world of Hameau, only to discover that Hameau is merely the tip of the enemy iceberg and that the battle is still very much undecided.  Cut off from their brethren, the marines fight desperately to hold their ground while millions of innocent civilians are caught in the middle ... ... And all too aware that whoever wins the war will determine the fate of the entire galaxy.