Agreed again. The most frustrating thing about the Eugenics War is that ,in part,due to mistakes in episodes of DS9 and Voyager people are forever trying to retcon them into the 21st or even 22nd century!Ever heard of suspension of disbelief? Trek always travelled back to the/our (relative) present, not some alternate version.
They came back to a 20th century that was very similar, but not identical to ours.
In their 20th century there was a Eugenics War in the 1990s, advanced spacecraft like the SS Botany Bay, and some software/computer guy named Henry Starling, just to name a very few examples of the differences.
In our 20th century there was no Euguenics War, the best spacecraft we came up with was the space shuttle, and we had Bill Gates and Steve Jobs instead of Henry Starling. Oh, and we had the fictional adventures of Star Trek.
TOS and Enterprise both make it crystal clear they were in the 20th century and were overt and were not the same thing as WW3. With Enterprise's focus on the WW3 era if the two wars were one and the same surely they would have told us that!