The US only recognizes its citizens. Switzerland only recognizes its citizens. This is true for most countries. However, this does not mean that you can obtain citizenship in another country and still retain your US citizenship. You must take care to always travel to the US on your US passport and not to run for high office in another country. You might have to serve in both the US and Swiss military. You wil not lose your Swiss citizenship if you have the citizenship of another country.
Consult with your tax advisor as to your US tax obligations if you become a citizen of another country.
Answered on Jan 17th, 2013 at 12:31 PM