You can not fail in creating a realm. You click a button and its done, from then on you are an independent realm and terms like "mother-realm" don't have a game-mechanics meaning anymore.
i think what he meant is... what if they fail to create a viable realm out of their secession. obviously the realm is still there. how to rejoin the old realm without all abandoning the new one and letting the capital go rogue/TO'ed/whatever.
