Originally Posted by
zara
You are correct regarding German citizens. But since different countries apply different rules/laws regarding their nationality there is no universal rule of thumb.
I was only referring to
weero's post who was only talking about German citizens. Of course other countries have different rules.
Originally Posted by
zara
If a baby is born in a car of the US embassy (=US territory) driving through Afghanistan, the kid will be a US citizen (territorial principle). If the baby's parents are German, the kid will be able to opt for dual citizenship because the German laws offer this option.
The interesting question is whether Afghanistan could also "claim" the child.
Originally Posted by
zara
AFAIK this is not quite correct. Like the US, a lot of countries (but not all of them) treat the airspace above their country as their territorial space.
Some other countries simply don't do that. In this case it doesn't matter if the plane was flying over Germany (both countries do not see airspace as their territory; correct me if I am wrong). Only if the first landing of an British airplane after the baby's delivery is, let's say, in Germany, the baby of British parents might opt for dual citizenship.
I don't know any country which doesn't claim sovereignty over its airspace. After all, if a country wouldn't then anybody could just fly there. In your example, the child of British parents which was born on a German plane above Germany and then lands in Germany will still not be a German citizen unless the parents have been living in Germany for a long time. Same would apply in Australia but not of course in the US or Canada.