I am sure they will be more than willing to attack their fellow Americans. Did not happen in USSR or Poland. You are counting on a big IF.
For everyone's reading pleasure: The Alaskan Independence Party http://www.akip.org/ H A W A I ` I Independent & Sovereign http://www.hawaii-nation.org/ New England Confederation Alliance.org http://www.newenglandconfederationalliance.org/ The Second Vermont Republic http://vermontrepublic.org/ Texas Secede! http://www.texassecede.com/faq.htm It only took me a couple minutes to find these sites. There are more. Have such movements always existed? Sure. But I think the frequency and membership has increased. Just earlier this year two New Hampshire legislators introduced a bill threatening secession... several other states followed suit. Not sure what came of it.
I remember reading this article a while back - just found it - better summary than the links I posted: Divided We Stand What would California look like broken in three? Or a Republic of New England? With the federal government reaching for ever more power, redrawing the map is enticing, says Paul Starobin http://online.wsj.com/article/SB10001424052970204482304574219813708759806.html
i have had a look at those websites and i think the new england one seems the most appealing and realistic as it is a group of states and effectively powerful.