Breakthroughs (The Great War, Book 3)

Breakthroughs (The Great War, Book 3) by Harry Turtledove. paperback edition. ISBN: 9780340715505.

Is it the war to end all wars - or war without end? It is 1917, and the United States are fighting a war on two fronts. In the north, from the Pacific to Quebec, US forces in the air and on land are locked in battle against Canada and Great Britain. To the south, at the heart of a line that stretches from the Gulf of California to the Atlantic, General Custer intends to do what none of his prececessors have done - to smash through the Confederate lines in Tennessee. Into this vast, seething cauldron plunges a new generation of weapons - submarines, barrels, attack planes, poison gas and flame throwers - changing the shape of war and the balance of power. Victory is at hand - but at a price that may be worse than war itself.