perhaps you were always meant to go back and kill those klingons. everyone that died was meant to die anyway.

NOT going back would have done far more damage if they were meant to die.

besides they're in sto'vo'kor now and loving it.

I think this quote sums it up nicely.

Well, now everything is back as it was, and if history doesn't care that our degenerate friend Fry is his own grandfather, then who are we to judge?

doesn't have much of anything to do with the discussion but that was one of the best episodes of futurama ever.

Predestination paradox.

/end

Talk of time paradoxes aside, I agree that we should be concerned with altering the timeline (even the case in which altering it creates bifurcations of the universe you're currently "in," which may alleviate some of the paradoxes).

These sorts of missions should be more about sneaking and cleverly completing your mission, rather than going around slaughtering things. You should at least be trying to not alter the timeline.

Personally I think they should rework it to have certain key events from the timeline in the mission, and if you change them, you FAIL! I almost hesitate to say this, but they should be obvious moments so you know to avoid them/restart if you screw up, and if you don't, you don't find out you failed until you get back to your own time and the world is significantly different that you're now hosed! Go back and try again...

Thing is, while I can see your point about imethods used (and I think the Devidian series did a reasonable job with this), there are two key differences in "City on the Edge of Never".

1) B'Vat has already outfitted himself with 25th century tech by the time you get there. The Klingons and their ships in the 23rd century are already more advanced than yours.

2) It turns out that your actions are the reason why Klingons have forehead ridges. So whatever you did was necessary for the timeline that already existed.