The Romulan War
I heard Brannon Braga talk at a Star Trek convention in the UK and he really had some interesting ideas when it came to the temporal cold war and time travel. He wanted to really mix things up in the 5th season and do things that hadn’t been seen in the Trek Universe before. One of the ideas was to have Romulan’s as the bad guys of the 5th season. This would have led to the Romulan War and creation of the Federation. The shaky, time travelling guy who helped the Suliban, would have turned out to be a Romulan and he would be getting heavily involved again.
Next: In A Mirror, Darkly