Ehhhh im not so sure about that. These days so many more countries are capable of mass destruction. When i was growing up it was pretty much us and Russia.
Actually, it depends how you define "mass." In fact, many countries could (and can) develop and deploy conventional weaponry capable of defoliating large areas of forest, rendering large areas uninhabitable, and killing tens of thousands of people. Then add biological weapons, etc. And you very likely had smaller powers capable of killing hundreds of thousands of people, although in a less "superpower" fashion than launching missiles from silos at home. They would have to get their hands dirty.
Even now, only the USA and Russia have "doomsday arsenals" that can destroy most life on the globe. The smaller arsenals in Western Europe, Asia, etc. can kill perhaps hundreds of thousands, maybe even millions, but do not compare to the US and Russia. So more countries have access to "superpower" arsenals, but the potential for "megadeaths" (not the band

) was always there, and the "doomsday arsenals" are still in the same hands.
Anyway, not sure this is a topic for discussion appropriate in this thread.
What could be more appropriate to a thread on where you'll be in 20 years, then speculation if the human race will finally destroy itself once and for all?
BTW, only just this morning i was watching some of the 50s/60s instructional videos on Youtube, and in particular the one about how one should duck and cover in case of an atomic blast! Boy am i grateful those school desks were bomb proof!
If you check out the
Prelanger Archive, you can find all sorts of older public domain instructional videos and movies, from the 30s through the 70s. Great stuff! Many of those on fitting into society are pretty amazing—really indoctrinated male chauvinism, etc. Watching some of those right wing movies about pornography is really the most awesome things in the world. Some of what passed for pornography in 1950s is now safe to show to children!
But I tend to think humanity will keep trucking on. We'll remain at the brink always, I think. Partly because with few exceptions humanity is dominated by selfish and greedy creatures who only look out for their own own short-term gain. But also because humans tend to be at their best when things are at their worst.
So I don't think we'll ever really go through with destroying ourselves completely, although I do think we'll push our environment past the point of no return, but I don't think that's going to happen in the next twenty years. So I guess in some ways, I do buy Gene Roddenberry's vision that we'll make it.

Although I think that in the real future, religion will be just as ubiquitous as it is now.