I feel like moving with the military, or going to an American school in a foreign country is less problematic than other situations. Starting at a new High School in Norfolk VA is different from starting at a new High School in St Louis. Going to college where you don't know anyone is not a problem because everyone else is in the same boat. Military brats and expat kids are much more receptive to new friends than their typical peers. If the new school has plenty of them, the experience is likely not so bad.