The only one I can think of is an all out nuclear conflict that decimates the US armed forces. I'm currently reading Rawles' "Patriots" and I'm only half way through it, so I'll give Rawles a break, but so far, no signs of any jack boots. I can't see it playing out this way. We currently have 3 million men at arms with 120 million to choose from should a draft be initiated. We know they practice and are prepared for martial law. They had US armed forces involved in Katrina and they've been commenting on the need for a greater role for the military in domestic affairs for years (where is the ACLU when you need 'em) I'd love to hear opinions on this, but IMO, if you're expecting You'd better be prepared to blend in and look like just another poor bumpkin living in the country.