Now do you remember me? I was Thukidedes and I wrote it all down 2500 years ago.

You youngsters can't remember the real wars like the continent war of ten thousand BC.
Now that was a war, we had weapons that have not been seen since. Today's H bombs are primitive compared to the fusion bombs the east side had at their disposal. The west side had a variety of beam particle weapons, including the dreaded silicon assault weapon medusa.
Even today you can go to the petrified forest to see the results of the tests that were conducted while it was being developed.
The east continent surpassed the western continents nuclear power by several orders of magnitude, The powers that be in the eastern continent wanted the western developments for their own purposes but the western leaders refused to make any deals, so the eastern leaders decided that the western weapons were too dangerous to be left in the hands of the westerners and the command was given that the western continent must be destroyed.
The superpower of the eastern continent had a smaller country that bordered their land, there had been some local skirmishes along the superpowers borders, the smaller country also wanted the western weapons because they were afraid that one day the superpower would simply take over their land.
The western leaders did not want the small country to have the weapons either, but through good espionage and bribery, the military men of the small country were able to execute a precise attack at the storage facility of the silicon assault weapons. In the raid they were able to obtain plans and some key parts of the weapon, from which they then were able to construct similar weapons of their own.
The great war was started and the eastern super power's intercontinental ballistic missiles obliterated much of the land and all but a handful of the western population.
The smaller border country was able to destroy the eastern superpower's armed forces by using modified silicon assault weapons and piloted aircraft.
That war devastated so much of everything that it took humans thousands of years to restart technology back on track.

War is not necessary for the destruction of civilization, take Atlantis for instance, it was a great place to live and work during its heyday, we had all the energy we could ever want, for any purpose that you could imagine. It was as close to utopia as the Earth could ever hope to encounter. At least that is what we thought until it was realized that the island was near a geologic fault zone and the huge amounts of concentrated nuclear waste dumped into the fault zone area weakened the Earth's mantle even further.
We (the scientists) knew that the end was coming but did not know how soon, the politicians and the general population did not believe or understand what we were talking about.
We were able to secure sufficient funds and manpower to transfer hundreds of thousands of tons of high grade nuclear waste into a selected area in the pacific ocean, it was deemed far enough "not to matter" even if it would melt its way into the core of the planet.
The time did come when Atlantis was destroyed and I now see that the Hawaiian islands occupy the nuclear waste dumping site.
Today we are heading towards somewhat similar situation with the misuse and misunderstanding of the nuclear forces and their eventual effects. :-)

In reality, I was very young when I and many other people almost suffocated in a bomb shelter, I would not want anyone to experience such a thing.

War is hell as they say, I do not understand why some people wish to live in hell.