In Action Comics No. 900, Superman announces his intention to renounce his US citizenship. His reasoning? After being accused of causing an international incident by flying to a fictional demonstration in downtown Tehran, Superman, seen as a stooge of US policy, announces to a UN assembly that he wishes to become a citizen of the world, and renounce his American allegiance.
And while that’s all well and good, I want to know is what will he replace it with? A passport from Krypton? Superman has to replace it with something, he can’t just be a stateless refugee. Also, he ought to be glad that he can fly on his own, because otherwise, there wouldn’t be a country in the world that would issue him an entry visa. Being an American may have baggage that comes with it, but global travel is one thing that’s invariably easier with a US passport.
So, sorry to see you go Kal-El, I hope you have fun in Mexico, or Wales or Sri Lanka or wherever it is you end up after leaving Metropolis. Ta ta!