Board Thread:General Discussion/@comment-79.52.61.188-20130415085048/@comment-1504072-20130415143353

Big Boss is a renowned figure by the 1990s, and considered the "greatest soldier of the 20th century," so its very unlikely he could secretly reassume command of FOXHOUND without anyone knowing. It's more likely that he and Zero reconciled, possibly over several years, but Big Boss had ulterior motives, setting up the betrayal that so embittered Zero in his later years. I believe Outer Heaven in South Africa was established as far back as the 1980s according to the original game, though this may have been retconned to the 90s now, I'm not sure.