Fully understand why you don't want to discuss specifics on this forum. However, it's also hard for us to give you a good answer w/o knowing the facts. Below are a few hypotheticals:
If it is an academic, conduct or criminal issue, that would be a big problem.
If it is a serious personal issue (i.e., roommate threatened you, you were assaulted, family member is dying, etc.), that can be explained to USNA and likely wouldn't be a huge issue -- depending on the facts.
If it is a less serious personal issue (broke up with BF/GF, think the profs hate you, don't like the school), that could be a problem b/c you would need to deal with similar issues at USNA and they don't want to think that you "quit" when the going gets rough.
If it is a financial issue, that is explainable and would likely not be a deal-breaker. But you should try to continue your studies at a community college.
The fact is that USNA will find out that you didn't complete your second semester b/c, as noted, you won't have grades from your college. They (not us) will want an explanation. Whether an offer would be rescinded depends on the reason.
No need to tell us. However, you should talk to your BGO or Admissions officer in advance so they know what's coming when no transcript is forthcoming. You might want to do that before you make the final decision on whether to return.