The Regiment is a novel by John Dalmas published by Baen Books in 1987.
[1] Lynn Bryant reviewed The Regiment in Space Gamer/Fantasy Gamer No.
It is a long book that could have benefited by being a bit shorter, but the prose reads easily and while Dalmas could have packed in more battles, there is plenty of action.
if you are looking for a good militarily oriented story that challenges you to think, you'll enjoy this book.
This article about a 1980s science fiction novel is a stub.