Board Thread:General Discussion/@comment-173.188.209.11-20131106151944/@comment-30088168-20161028005223

Yes it's post 4 just saying that the "great war" is halo war. (I am unnamed user quoted above)

Did mention its  post 3 at least. Most likely been since season 3 at least. With how they weren't at war when  they first met the aliens.