Question: I just renewed my passport. Why does the U.S. Department of State send the new passport and the old passport separately? I know the Postal Service needs all the business it can get, but two mailings instead of one seems wasteful.
Answer: Like Fink, I just got a new passport and was puzzled about why it arrived in one heavy envelope and the documentation I had provided in another. I was smugly certain it had to do with security, and in my smugness, I disregarded the lesson of Ockham's (sometimes spelled Occam's) razor: The simplest solution is usually the correct one.
Here it is: Passports are printed in a different place from where the passport is adjudicated, the examination of documentation. For security reasons the State Department does not provide details of this adjudication process.
But consider, for a moment, what is considered proof of citizenship: The State Department's website says you can use an old, undamaged passport, a certificate of citizenship, a certified birth certificate, a consular report of birth abroad or certification of birth, a naturalization certificate or a certificate of citizenship. Then think of friends, family and others who don't have a U.S. birth certificate. My friend Vic, for instance, was born in a displaced persons camp in Germany after World War II, and my friend Raoul was born in Asia and became a U.S. citizen. Adjudicators must know when to become suspicious of documents of any stripe, never mind a document issued in the chaos of post-war Europe.