How will the end come? I think for humanity, as for individuals, it will be "with a whimper and not a bang," and furthermore, it will be a predictable downslide.
Very few deaths are truly shocking, or unexpected. Cancer runs its course, old age leaves little doubt that the end is on the books and will "be here shortly," and even war is a question of which bullet, not that a bullet enters the forebrain and liquefies it, banishing life to a memory from a separate observer. Similarly - it seems to me - a society in degeneration will not blink when the decay has run its course, but will shrug with a release of tension that could approximate relief, and say "So it goes."
Insert photographs of AGM-109f units penetrating buildings, soldier hurriedly applying field dressing in order to realize it's too late and move on, another family looking into the pit and trying to ignore the cracking gunfire behind them until the last possible moment.
Will our end be by war? I think not: I think instead it will be a gradual unknotting of ability for a society to take care of itself, resulting in a breakdown both sublime and eventually, profound. The only conflict will be the continuing problems which we stifle to end the loss, in effect ending debate on vital issues and thus smashing portions of our necessary social and intellectual infrastructure. Symbols will replace reality. Reward will replace motivation. Control will replace autonomous agreement on values. And when those linchpins are pulled? The guts will fall out.
We are in the age of unravelling, yet we're still in control. I suppose all we need to counter this trend is what kills any trend: enduring values and something to believe in, something to work for. All it takes is for one strong voice to speak up against the suicide. But already, it may be that none of us are motivated.