Aw, it's all cool now, dawg. Remember when he renounced his citizenship? Here's Supe in a recent issue:

Bleeding Cool, which brought this to everyone's attention, transcribes the entire passage:

But it's a different book and storyline, so he's still not an American citizen in the other one. This is why I could never enjoy Superman as a kid. In one book he's married to Lana Lang, then he's not, then it's "What if Superman was Lois Lane's Uncle?" or "What if Superman was Perry White's Tax Accountant?" and none of it ever really happened.