Yes, every side in every war says essentially the exact same things dating back at least many decades, and I suspect centuries, if not millennia.
This notion of 'defending the homeland' is in many ways a modern concept.
Plebes did not view the local principality as 'theirs' - another prince coming to take over just means a 'choice between lords'.
Obviously, it's different if the Romans are coming into German tribal areas, but, 'state nationalism' as we undertstand it is a modern concept.
Invading people to 'spread an idea' was mostly an Islamic/Arabic thing, and then Napoloenic in modern era. Very rare in history.
And propaganda is usually pointless, it's obvious who is invading who - there is no 'media' to control the narrative within, obviously, the local folks in towns were instructed what to say but this is low-grade propaganda.
I'm not sure what the peak of state nationalism was, but I think we're well beyond it. There's not a country in this world that I'd die for, I don't feel even remotely bad about that, and I think this view is the norm. In the future all the borders and systems we know will be long since shuffled around. Why should I care about perpetuating any given state today? Give me a place where I can reasonably safely raise a family and earn a living, and I'm good to go. I couldn't care less if it's under El Presidente or Gandhian Democracy. I'd obviously prefer the latter, but not to the point that I'm willing to die to prevent the former.
I'd also add that I think we're probably beyond it on the order of centuries. Every war since (and including) the US Civil War has relied heavily on forced conscription. If the only way you can get people to fight for you is by force, then clearly there's no grand ideology anywhere but in the propaganda.
Well then you are just myopically stupid and willfully ignorant of history if you DGAF whether you live in a democracy where priorities are determined, at least attempted to be determined, by the people, vs by an autocrat.
And you obviously DGAF about your children, or the future of society.
Under Autocracy everything gets worse, down to the point where the people cannot tolerate the starvation and revolution is fomented.
Of course there is the occasional benevolent dictator, and those systems have the advantage of being able to do better long-range planning and mroe rapid changes of plans. But they are not stable and inevitably a malicious or greedy dictator or oligarchy takes over, and things start getting irretrievably worse, and the population starts dying of impoverishment.
Does it really matter if you die of impoverishment from the leader's stealing or war from the leaders' theft?
The only way forward for humanity is for democratic governments to ensure continued and improved democracy AND fight expansionist autocracies to contain and eventually eliminate or convert them.
If we fail to do that, it will be only years before life devolves into feudalism of a few lords and everyone else hopeless peasants. And no, you won't be one of the lords.
Then there's the UK - I'm not even sure of who their latest leader is. They go through PM's faster than some people change their underwear, and they all rather smell like shite. In democracy the whole ideal is that you can pick another direction with new leadership, but when it's always the same crap with a difference face - you're eventually going to see things go boom. In the US we tend to have popular leadership, relative to Europe, but the sides are becoming so antagonistic and divided that we're basically a powder keg waiting for some sufficiently tumultuous event to set it off.
In general I think Plato's views are highly insightful, and strongly recommend "The Republic." In his view, systems are inherently cyclical, and all will repeatedly end - often in a rather unpleasant way, and transition to another system, eventually cycling back where they began only to begin the process again. This class warfare nonsense is meaningless to me. I couldn't care less about being a lord or a peasant. I want to raise my family, have a roof over my head, and frankly I don't need all that much more to be relatively content. People who want will never stop wanting, no matter how much they have. I find it a very sad way to live, and hopefully can instill the same values in my children.
Again WW1 is such a great example of so many horrible things in the 'metagame' of the war itself. The propaganda there was framing it, genuinely, as 'The War to End All Wars.' It's easy to mock now, because not only did it end nothing, but led directly to the worst war in modern human history, but you have to keep in mind that the propaganda was making this literal claim, and you certainly had some significant chunk of people that believed that - perhaps some that even died for it. But alas, no 'this time was not different', as usual.
And I've had the opportunity to live through far worse, yet life remained pretty decent throughout outside of times of violent conflict, which I've also gotten to live through. Such conflicts are probably unavoidable since it will always be the final way in which irreconcilable differences have one side impose its position, but should be terminated at the earliest reasonable point, and certainly kept as small scale as possible. But I think that once you get to experience the worst, you start to realize that all of the political stuff, though fun to debate about, is mostly just petty people politicking for power with perfidious propaganda.
This is not to say all systems are the same. They are not, and I do think some are better or worse than others. But they run far closer than most who have never experienced 'the other side' think. But I also do not think we should all just aim for the 'best' system, because all systems have their pros and cons, even more so when speaking of a given moment in time. And so having a diversity of different system is the best way to ensure we never end up as the worst of worlds in terms of outcomes, even if it also ensures that we'll never end up as the best of worlds.