The sort of war we should expect on US soil will likely be 4th Generation warfare; likely civil war as the remnants of the US Empire start seceding from one another. Such a war would likely be one of secessionists against federal troops. In some cases, you'll have a rebel city breaking away. (Remember that the Revolutionary War had only minority support in the beginning, something like 10%.) In such a scenario, expect organizations of the Hezbollah model running the show. They'll have a vested interest in maintaining the creature comforts of modern life, or be faced with some unhappy citizens. The vast majority of Americans will go with whoever keeps them comfortable. So maintaining cable TV, water, sewer and INTERNET connections will be paramount. I'd think such a rebel organization would want to build a mesh network throughout the city with multiple satellite connections so as the network remained as decentralized as possible. If not, and the enemy knocks out the internet, who cares? A city in the middle of a low intensity conflict (look at Baghdad following the toppling of Saddam) will have a lot of other shit on their plate. But even then, I'm sure SOMEONE will be able maintain an internet connection, somehow, providing a link to the Bitcoin network and allowing for the exchange of money. This would probably fall under the control of the local Hezbollah-like militia. It would simply be another one of the services they provide (along with social services, city works, death to the enemy, etc.)