Can a foreign student enroll to a Military Academy?

Answer 1

Going into a military academy is free. Upon entrance, you can be commissioned as a second lieutenant afterwards. Even if you don't stay in and become a flag officer, it would look good on your resume if you leave. But keep in mind that there are some negative points about going to the military. When you become drafted, you basically have a contract with the government and most likely, you will not be able to get out of it - when that happens you can be in a situation that you don't want to get out of.

Answer 2

Yes, they can. Example: West Point or the Naval Academy may have up to 60 foreign students at any time studying there. The students come from a list of countries approved by the State Dept. and the DoD, and the student must be sponsored by a government official.

This is controlled by public law (Title X of the U.S. Code), so it's safe to assume the other military academies follow suit.