It supposed to be our future, The references to "past" events are usually ignored when our heroes journey to the present. Which is why episodes taking place in the 80's, 90's and 00's make no reference to the Eugenics Wars, Augments or the destruction caused by the wars*. Instead they look like the world right outside our windows because there is more mileage to be gained from show our heroes in contemporary time than some fictional version created decades before. If Star Trek is still being produced in the 2060's, you can be sure there won't be a WWIII as part of the narrative.I've heard this argument before (Gene Roddenberry himself said it no less) and I partially agree with it except that star trek isn t our future, they had a nuclear war in the 21st century (I think) so it isn't our future. Anything in our future which ends up looking like star trek is a star trek reference.
* Yes there is a model of the Botany Bay in Rain Robinson's room, but it's set decoration and not a plot point or even mentioned.