Silent Order Iron Hand by Jonathan Moeller

The galaxy is at war, but wars are won and lost in the shadows.
To the galaxy at large, Jack March is a privateer of the interstellar Kingdom of Calaskar and a former Iron Hand commando of the malevolent Final Consciousness. In truth, he is an alpha operative of the Silent Order, the most efficient and feared intelligence organization in human space. When there is a crisis, Jack March is the man to call.

But there are many forces that wish to enslave or destroy humanity.

And when a mission leads March to a lawless asteroid space station, he might be the only one left to stop those forces...