I think the reviewer is recapping Faust here:
[The ACW was] a bloody war of attrition, where defensive firepower so overwhelmed the offense that—at Antietam and Fredericksburg and the Wilderness—the soldiers mostly just stood there and watched each other die.Or brewed coffee in the rear areas. Or read about the battle from the easy chair of their overstayed leave. Or talked about it in the tavern while on a pass issued by their duly elected officers against the regulations of the army commander. We're talking about that Civil War, right?
Strange, though, that the New Yorker couldn't roll out one of the usual mealy-mouthed ACW celebs to heap platitudes on This Republic of Suffering. Maybe Faust is non-establishment.