I think secession is the easiest, IF the State being seceded from doesn't fight it (as the North did in the U.S. Civil War). When the Soviet Union broke up in 1991, that's how: secession of everyone, like an explosion. The whole recent Ukraine thing was Putin's effort to get that one valuable part tacked back on. Scotland tried to secede recently, but lost the vote, barely. Some of them are still agitating for secession. There are and have been secession movements all over the world, and they often work: Bangladesh seceding from Pakistan some decades ago, for instance. This country is deeply geographically unstable, with the Left Coast and the East Coast similar but widely separated, the South different from the Midwest, the northern plains nothing like the left coast. I figure six countries. In a weekend. It has to happen fast, as all those other secessions that seceded did -- a very few days. Because otherwise, people will stop it. But the economic and defense advantages to this large country are huge, so there's a lot of friction against it.
But it's too heterogeneous to survive now.
