should not be about war, but nor should combat be utterly absent either. Knowing that war is never going to happen eliminates drama. It's far more dramatic not knowing whether physical danger exists, and it's important and interesting to explore how to diffuse or otherwise resolve situations, once some level of hostility has broken out. Certainty in outcomes, whether in that war will always be avoided or in that war that breaks out must necessarily be protracted total war, is the enemy of drama, especially ongoing series drama. The exceptions I'm aware of are stand-alone one-offs such as On the Beach
or post-apocalyptic series like The Walking Dead,
and they don't have tones or formats compatible with Star Trek.
So, as to whether Star Trek
should have a major
war again, I say no. Such a thing would exhibit certainty in outcome on two levels.
One, we know that the war is going to keep going. To borrow an observation by Douglas Hofstadter, it's like looking at the number of pages left in a book and knowing based on how many pages remain that the attempt at resolution is going to fail. It thereby undermines drama. If the premise of the show is that there's a war, you pretty much know that it's going to go on for at least almost the whole show.
Two, we know that the Federation is going to win anyway. So, why did we waste our time jumping through all those hoops?
Besides all that, it's downbeat. In relation to Star Trek,
the interesting thing is how the combat is resolved. Drama and suspense in the revelation of that is good, because the show must ultimately function as a drama. But it's not the only subject worth mining for dramatic purposes.
For at least these reasons, the answer is no. A major (hot) war, and especially a show revolving around a major war, is not needed in Star Trek.
Cold war is interesting dramatically, because it can always get hot and you never know when or where, and you don't need as much to have it resolved by the end of the series.