My charming bride, Riza, is a naturalized US Citizen. Watching Peter Arnett, she remarked upon the oath that she (and Mr. Arnett) had taken when they received the gift of US citizenship. It is up on her blog and is well worth a read.
"I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same"