If you don't get this thread then you should read it agin. They detained this particular US Citizen in Germany because he commited a crime under German law. Using fraudulent documents to enter Germany is a crime, very simple. And a person who is no longer a German citizen trying to use German passport is commiting fraud. That's why he got arrested. Makes perfect sense. If you rob someone in Germany, you will be arrested if caught. US citizen or not - doesn't matter. Well, using fraudulent documents is a serious crime, just like robbery. Makes sense now?
And you CAN loose your US citizenship. It's very hard and unlikely but you can.
And once again, DON'T give people wrong advices if you don't know what you are talking about. His wife WILL NOT have Ukrainian citizenship any longer, as soon as she becomes a US citizen. Not under US law (US law doesn't govern Ukrainian citizenship), but under Ukrainian law. And if she attempts to use her Ukrainian passport to enter Ukraine, she can be in some serious trouble. Please read the thread again - all information is already here.
Redneck-NOVA got a reaction from Brother Hesekiel in Dual Citizenship