Write about...What is wrong with gays being the military? Because they're surrounded by other guys/girls? Well when I'm at the grocery store I don't see a problem with gays being around other girls/guys.
Lol I don't know if that makes sense, but that's my analogy.
Well i would start with don't ask don't tell, why it was implemented, the effects that it had, and why it was repealed. Perhaps discuss differences in society's opinion of homosexuality having an impact on "don't ask don't tell". DADT should be your focal point.