Ambush in the Ashes — William W. Johnstone

A rebel patriot force goes to battle against a resurgent Nazi army in Africa in this post-apocalyptic adventure by the New York Times bestselling author.
 
After a nuclear strike decimates America, retired soldier Ben Raines refuses to let his once great nation be snuffed out. In the ashes of the apocalypse, he and his Rebels face off against the anarchists and barbarians who seek to destroy what's left of the Red, White and Blue. But the threat to civilization knows no borders.
 
Now, Raines's battalions are positioned to advance on Southern Africa in pursuit of Bruno Bottger and his neo-Nazi armies. Those seasoned SS combat stompers are on the verge of turning Hitler's nightmare into a new and terrible reality -- unless Raines wipes them out first.