Taking my young nephew to his homeland for a visit

score:7

Both of you need proper documentation to enter X. Since you are both citizens of X, that should be straight forward for most countries. Make sure that X allows dual citizenship (not all countries do).
Both of you need proper documentation to re-enter the US. That's easy for you since you are a citizen but you need to read up and what's required for minors from country "X" with a J2 Visa.
You should carry a notarized letter signed by both parents that you are allowed to travel with your nephew and make. You may not need it, but it's a good document to have.
Discuss with the parents how you should handle things in the unlikely case there is an emergency. Can you make medical decisions? How flight changes, travelling around in the country, staying at certain places, etc.? Make sure this is properly documented and you have all required authorizations, just in case you need them.
When booking flights check with the airline if they have special rule for kids travelling with an adult that isn't their legal guardian.
Have fun on the trip: that's a great bonding experience.

Hilmar 85625

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