I assume all overseas US military bases don’t have maternity facilities? And not all US military personnel overseas are assigned to bases. So some percentage of mil offspring get birthed on “foreign soil” I’d think - in foreign hospitals. So we need to allow for that.
See post #359 for an explanation of what happens for military born overseas.
They are usually told to go home to have the baby if they want to preserve NBC status.
What is described in post #359 is a naturalization process.
Not natural born citizen.