I don`t think we should expect every alien civilization to become more like “us”, to share our way of morality. I find the Klingons interesting because they have different views and I can understand them even when I don`t agree with them. I don`t see why a warrior culture like the Klingons is bound to collapse.
Who was talking about morality? I'm talking about simple practicality. In purely economic terms, a nation needs a reliable supply of strong, healthy, productive adults to have a healthy economy and social order -- not just in terms of a labor force, but in terms of people with the education, skills, intelligence, etc. to innovate new technologies, manage the government and social institutions, etc. If too large a percentage of the population dies off or is crippled in violence, then the work force and brain trust of the society are diminished, and prosperity and progress suffer as a result. This is why wartorn regions like the Mideast currently (or Europe a millennium ago) are mired in crushing poverty, dominated by oppressors and fanatics, and unable to function on the same level geopolitically as the more peaceful, prosperous states.
All the self-induced chaos and destruction within Klingon society are not only killing off their population base and cheating them of healthy, vital, dynamic individuals who could be building things rather than blowing them up, but are wasting resources on violence and destruction that could instead be invested in growing their economy, advancing their technology, and improving their standard of living. I can't believe I seriously have to explain that it's more wasteful and costly to be destructive than productive.
Wars are expensive things. Bush's invasion of Iraq totally destroyed America's Clinton-era budget surplus and saddled us with record-breaking deficits that have now reached the trillion-dollar level. And that's a war that doesn't even touch American soil. Given the constant warfare the Klingon Empire engages in with its neighbors and within itself, I find it implausible that they even have a functioning economy. Even allowing for different economic systems in the future, I'd think they must be drowning in debt. Even if they had a moneyless, replicator-based economy like the Federation's -- and I'm not sure they do -- the profligacy of constant war and infighting would be difficult to sustain over the long term.
A certain balance is necessary in each culture and I think it is a good sign that Worf and Martok, for example, are working on that. But otherwise I don`t see a need that the Klingons have to give up the way they live or their society will self destruct.
Giving up pointless murder isn't the same as giving up the way they live. A culture can value honor and strength without wallowing in blood and death. Indeed, we know that's already a part of Klingon culture. We know from ENT: "Judgment" and from
A Burning House that there are large segments of Klingon society who derive their sense of honor from things other than violence, such as practicing law or working a farm or composing operas. The battlefield can be the courtroom or the land or the stage, and honor can be won and strength proven in many ways beyond killing. That is
already a basic part of Klingon society, and according to "Judgment" it was a widely accepted part until the warrior caste took over and marginalized it. So I'm not talking about the Klingons giving up the way they live -- I'm talking about them going back to the way they
used to live before the warriors took over and forced everyone else to give up
their ways.