I beleive there is a regional US carrier moving from San Diego or Santa Ana to Dallas as we speak.
Also a big example is Air Berlin moving from Miami as Air Berlin USA to Berlin when politics calmed down.
I support this.
Moving from one state to another is one thing. But moving from the USA to Japan is another. With the Air Berlin case, they were a charter airline with only 90 employees when they "moved" their operations (when they actually were bought out by a German entrepreneur and then restructured into a German company). What would happen if a major airline (lets say Delta) were to move all of its operations from the US (and it's HQ in Atlanta) to Japan and base itself out of Japan? Their fleet would need to drastically change, and the Japanese government would most likely figure out a way to stop this if it ever happened (i.e. to protect the Japanese carriers ANA, JAL, etc.).
Possibly in the case of countries splitting up, this could be an idea.
(As when the USSR breaks up, Air Ukraine doesn't want to be stuck based in Moscow... )
In this case, what could happen is the choice of choosing your new home country out of a list of countries that came out of the USSR break up(i.e. choose between the 15 countries that followed the USSR such as Estonia, Latvia, Lithuania, Belarus, Moldova, Ukraine, Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, and Russia). While this is not exactly what would have occur in real life, it does avoid the realistic fact that many Soviet Airlines went bankrupt and never restarted. At least this gives those current airlines a chance.