Concept illustration of tower condos and perimeter wall house. (iiicitadel.com/Supplied)

Foot soldiers in America's culture war are taking to their bunkers.

As U.S. President Barack Obama's administration plans new firearms restrictions in answer to the Newtown massacre, one group is calling for survivalist-minded families to apply to live in 'III Citadel' - a planned fortified city to be built into the mountains of Idaho. The main industry would be - you guessed it - firearms making, and residents would need to prove their proficiency in gun use.

"The Citadel is primarily designed to defend against a grid-down, economic collapse scenario," reads one of the many pages on the website calling for recruits. "If living in an affordable, safe, well-prepared, patriotic community where your children will be educated in school rather than indoctrinated, consider the Citadel."

Since the start of the great recession, precious metals and firearms are some of the only products seeing a sales boom.

The main problem with creating utopias separated from the rest of society is one of economy, says one expert.

"In the case of III Citadel, it sounds expensive. It seems unlikely to me that you could get very many people to move to a self-sustaining city in the middle of nowhere without some pre-existing infrastructure," said Jason Sorens, founder of the Free State Movement and an assistant professor of political science at the University at Buffalo.

While some religious groups have a history of success in building their own communities, Sorens suggests survivalists are better off moving en masse to established towns with industries.