Originally Posted by
kebosabi
Like Japan for instance.
Or a lot of people in Scandinavia. The Scandinavian systems of citizenship by descent -- and that is mainly what they do when it comes to births on their territory or even outside -- do care where people were born. [Scandinavian citizens born outside of Scandinavia are not all treated the same as Scandinavian citizens born in Scandinavia when it comes to the ability of their children or their children's children to have Scandinavian country citizenship as well. And, like Japan and some other parts of Asia, they also use a feudalistic-type population register system.]
Originally Posted by kebosabi
Japan, doesn't really keep track where each individual Japanese citizen was born because they do not have a jus solis system like the US (born in the US, you're American). Instead, they go by jus sanguinis where it's the blood of father and/or mother that matters to be Japanese (i.e. father Japanese, mother American, born in Vancouver, BC, child is legally Japanese, American, and Canadian).
Well familiar with all that; but your last "is" above should be "may be" -- the child's citizenship status also depends, amongst other things, on the parent(s)' status in Canada at the time of the birth, when/how long the American mother has lived in the US, and when the child was born.
Originally Posted by kebosabi
Overall, it's simple for the American to get an American passport to enter Japan.
Indeed, which is why having a passport ordinarily makes sense for travel from most countries to most countries.