Seeing how humans are not prophets or gods and don't have the power to predict and change the script - no matter how 20/20 hindsight is - such hypotheticals are, in the end, only ways to avoid looking at the problem: many times, pacifism is suicide with no gain.
And, of course, non-violence has other down-sides, as well: for example, non-violence allows Assad to do whatever he wants in Syria, helped by the pacifism of western nations.
That argument just circles back on itself because if we only restrict our arguments to "the present" you can never say when violence is the best solution. Shooting Nazis is the best solution at Point X but if we're at Point X, why not go to point V or U? You don't prove much about violence other than saying it's right in that very specific instance
I don't even disagree with you that much but violence is not necessarily a good answer. It's just an
One needs look no further to the particular War on Terror. NOT, as you might think, me saying the USA is finding it a poor solution to its problems. No, it's a poor solution for the individuals resisting over in Pakistan's hills.
The tech level divide can (and does) reach a certain point where violence, in a good/bad/neutral cause doesn't do anything even if your resolve is strong, because resolve/violence does not guarantee victory. Tech can overcome those. It's an unromantic notion but violence is no more inherently effective than any other method. When planning to wage war, you need to have a reasonable chance of victory.
Indeed, DS9 was very...let's say, mature, by star trek standards.
It most definitely departed from the 'pacifism is always the solution' mantra which Christopher seems to be exposing.
It was both the benefit and the flaw of the Borg, too. The Borg were cool because they were unreasonable and antithetical to the Federation. Simultaneously, those very facts meant they undermined the whole theme of the setting.