“his mom is American so I don’t get the citizen issue”
She was living overseas and had a baby overseas. That makes the baby not an American.
A child born outside of the United States to one American citizen parent and one non-American parent, may be entitled to citizenship providing the American citizen parent had, prior to the birth of the child, been physically present in the United States for a period of ten years, at least five years of which were after s/he reached the age of fourteen.