The Old Mixer wrote:
Really, the seeds for the Klingons displacing the Romulans were planted back in season 1 of TOS, when the Klingons were created for "Errand of Mercy" to displace the more makeup-expensive Romulans. The Romulans were only used in one more significant appearance in TOS, whereas the Klingons became the Federation's main foe.
Then in TMP the Klingons got their makeover. We didn't get much of look into their culture or attitudes in that brief appearance, but surely the new look informed how the Klingons were treated afterwards...from that point on, they demanded to be more than scheming moustache-twirlers...and they demanded to be used more than the Romulans, who were pretty much stuck looking just like Vulcans.
We can thank TNG for bringing the Romulans out of mothballs at all, however they chose to portray them. And that was only after the major misfire of trying to set up the Ferengi as a worthy adversary.
Over the course of Trek history, the Romulans simply got a heck of a lot less development. They became known for being manipulative pretty much by default, to differentiate them from the TNG-era Klingons. The one capsule description of the Romulans that sticks out to me is when Picard says "It's always a game of chess with the Romulans." Really, this could describe the TOS Romulans in "Balance of Terror" as well. One thing that is often overlooked is that the sub-commander in that episode was being portrayed as an individual who didn't agree with what his people wanted him to do.
Well first, Klingon honor is very relative to the klingon in question, and story being told. It seems very fickle, and what is and isn't honorable sometimes is very fluid and changing.
Also, are people in Western Civilization the same people they were 70 to 100 years ago? You can cite the UK and French Empires after WWII as examples, and even the US in its apparent downward spiral as a world leader. As a nation's world status changes, so does its attitudes and social mores. So why can't the Klingons have changed between TOS and TNG?
And actually, we did get some explanation for the Klingons changing (albeit somewhat a retcon) in TUC, when the moon Praxis blew up, that changed the entire Klingon economy. They no longer could afford their military budget, which means they shifted from an expanding empire to a world struggling to survive. And later on, the federation came to the Klingons' aid in both the battles of Khitomer and Narendra III. So, with the Federation helping the Klingons both economically and in battle, as well as opening up trade and cultural influence, perhaps the TNG era Klingons had some of the Federations' attitudes rub off on them, and they became more enlightened than the TOS era Klingons, at least relatively speaking?
Actually I think this is definitely a very reasonable explanation.
But it still feels, for me, like the Klingons being so
obsessed with tradition feels like a bit of an ass-pull. Unless (as I've theorized in other threads recently) we take it that they are all playing up the 'honorable Klingon' bit for the benefit of outsiders? Offering up a kind of Disneyland Klingon Empire, something that looks kinda like the real-deal but is really just pomp and pretense?
I know it seems an ass pull, and maybe it is to an extent, but really, the Klingons were not featured all that much in TOS. We are talking out of 77 episodes, less than 5, I think, and of course, the movies. So, to me, TNG is really what defines what the Klingons are.
But for an in-universe explanation, it is possible that the Klingons were once more honorable during the times of Kahless, and "devolved" by the times of Enterprise and TOS, and with honorable thought and action making a resurgence and became more main stream by the TNG era.
Maybe what happened to the Enterprise and TOS era Klingons was sort of like what happened to the Cardassians: a once honorable people who were cultural and artistic, that shifted to a militaristic society once hard times were upon them. Human history has countless examples of this.
So, at least how I rationalize it, once the Klingons were on the brink of losing their world, the Klingons as a whole people reassessed their situation, and saw that their expansion as a dishonorable empire caused their situation in the first place, and between that, and feeling both a gratitude and indebtedness to the Federation, by the TNG era, the Klingons changed their ways.
Maybe a real world analogy to the klingons changing would be how humans are now realizing that global climate change is caused, at least in part, by human pollution and are now taking steps to become more conscious of using more efficient means of transportation and being less wasteful of their resources. Hence the term "going green." That attitude didn't really exist 30-40 years ago.