From Trek TodayMy Entertainment World posted information ostensibly from an online auditon listing, calling for actors to play a leader and a reporter at a historic United Earth conference and for a guest star to play "Colonel Green: 40, male," whose image appears on a monitor from a speech he gave a century ago. The villainous Colonel Green appeared in the original series episode "The Savage Curtain", which also featured historical figures such as Abraham Lincoln and Vulcan's Surak.
A century ago would put it around the time of the Third World War that was referred to in "Encounter at Farpoint" and
Star Trek: First Contact. Actually, bringing up Green here fits, since part of the story involves a Vulcan-Human hybrid baby and Colonel Green was known for waging a "genocidal war" according to the Excalbian in "The Savage Curtain."