He well could become a Marine officer, and if he does, he could be a good one. But one step at a time. Let him cherish, first, some moments spent with the men and women from the rank and file of America that he may someday lead. In fact, that's the way it works. Armed forces enlistment and honorable service expedites achievement of formal citizenship under the laws thereunto pertaining, and U.S citizenship expedites military commissioning. He looks like a really good guy for our side, but let's size him up in the usual ways for his sake and our own. This is a complex world now, and the old saying "when in doubt, check it out" applies. So let the proper authorities check him out and let us meanwhile hope he is a jewel, as he certainly seems to be, and joins us, the few and the proud.
Wise words. Thanks.
Unfortunately, he cannot become a Marine officer unless he gets the US citizenship. I have full understanding for this requirement, we Germans don´t have any foreigners at all in our military. So it´s just fine that the US only wants its citizens to lead its armed forces. Becoming a US citizen is the critical point, so when he leaves our army next year, he a) needs a permission to serve in foreign forces by our Defense Minister (that´s not a problem for those who want to go to NATO partners) and b) can only become an enlisted.