Casca 62: The Nationalist by Tony Roberts

Civil War comes to Spain with the traditional monarchists, Catholics and landowners battling against a popular front of republicans, democrats, anti-royalists, anarchists, socialists and communists.

Casca, calling himself Carlos Romano, is part of the Army of North Africa that is under the command of General Franco who is one of the leaders of the anti-popularist revolt, and Casca finds himself dragged along with the rest of the army to the Spanish mainland to fight the government forces.

Not that he doesn't mind; his staunch anti-communist feelings means he has a good reason to fight on the side of Franco's Nationalists and his attitude hardens even further when he falls foul of a Soviet advisor working on behalf of the Republicans.

Casca's aims widen from winning the brutal, pitiless war to also getting even with the Soviet advisor for deep personal reasons, and he won't stop until the Russian is dead by his hand.