In what world are Iraq / Afghanistan good "comps" for the US military's performance in a civil war? Those countries had a virtually endless supply of young men who wanted to die for their cause, due to religious fanaticism, and were willing to do anything to make that happen. Who is going to fulfill that role in this hypothetical civil war? The US military was also faced with 10,000 km long supply lines and extremely rugged terrain where no one had any local knowledge.