Jusqu’ici, tout va bien…
On the 7th of July 2017 — the U.N. effectively outlawed nuclear weapons . 122 nations voted in favor of adopting the treaty, which will be formally signed later this year in September.
The treaty prohibits states from developing, testing, producing, manufacturing, transferring, possessing, stockpiling, using or threatening to use nuclear weapons. It also prohibits them from assisting, encouraging or inducing anyone to engage in any of those activities. In addition, states must not allow nuclear weapons to be stationed or deployed on their territory.
None of the countries holding a nuclear arsenal today (including the United Kingdom, USA, Russia and Italy — which, as a NATO member, hosts US nukes on its soil) signed the treaty, in fact they actively condemned it and it is very unlikely that they will be joining any time soon. However, this is a landmark moment, as these weapons are finally and officially recognised as inhumane, and officially stigmatised alongside biological and chemical weapons. This is needed to change the public opinion’s stance on this topic, especially in the climate of heightened international tensions we live in.
Despite the end of the so called Cold War, as of today it is estimated that Russia and the USA alone possess roughly 14 thousands nuclear warheads, a sizeable portion of which is ready for launch at any time . Both countries are actively seeking to improve their arsenals with large investments and improved capabilities . The fact that the stockpiles have diminished from a few decades back should not fool anyone, as the efficiency / lethality of the remaining systems is continually improved.
In just a handful of minutes, each country commanding a nuclear arsenal is capable of launching a massive nuclear strike against others, an action which would eradicate humans and most other life forms from the planet. It is important to note that this event might happen voluntarily (as a result of a military escalation) or even involuntarily — by mistake. There could be a fault in one of the very complex systems controlling / monitoring these weapons, human error & misinterpretation, or a combination of these.
In fact, since the first bombs were detonated in 1945, in just over 70 years there have been countless occasions (     for an idea of the scariest ones we know about) where we have been just a hairline away from extinction.
Not to mention incidents , lost warheads (yes, apparently you can lose nukes!), stolen weapon-grade material  or even plain and simple indolence , or sheer ignorance on the topic  . We are still here just out of a whim of fate — this is not sci-fi, or a movie scenario. These things have happened, and could have easily gone the other way.
Nuclear deterrence between countries is essentially the same as having a bunch of people holding a gun at point blank range to the others’s face, finger on the trigger. At the same time, everyone is shouting at everyone else that it’s all fine,that there’s no need to shoot, hoping that no one misinterprets another’s sideways stare, or that another guy doesn’t trip on himself and pulls the trigger by mistake. It is completely INSANE.
At the same time, there are also rogue actors (or terrorist groups) that can seep through the cracks of this humongous, mass destruction system, and steal small quantities of weapon-grade material to construct an improvised nuclear device. On this topic, a prominent expert states that in his opinion there is an “even chance” of a terrorist nuclear attack happening “in the next 10 years” . To build the same bomb that was detonated over Hiroshima, enough enriched Uranium as that contained in just 8 small cans of beer would be required 
Finally, even if you believe that we will never (voluntarily, or involuntarily) annihilate ourselves in a global thermonuclear conflict, please remember that even a “small scale” (if that can be said) nuclear conflict is enough to cause a worldwide disaster. According to studies, a conflict between countries using “mere” 0.03% of the global nuclear arsenal (roughly 100 “Hiroshima” equivalent bombs) could be enough.
Assuming these weapons are used to hit urban built areas, the ensuing destruction and firestorm would create an inordinate amount of smoke, sufficient to reduce the amount of sunlight reaching Earth (decreasing the temperatures over decades) and causing massive depletion of the ozone layer around the planet. This ignores the actual effects of the bombs (in terms of radioactive fallout for example)
In a nutshell, this theory is called “Self-Assured Destruction” (SAD). What this means is that even a “lucky” attacker (managing to hit first and obliterate the enemy, with no retaliation) would still condemn themselves and billions of others to a catastrophe on a global scale . This is generally known since the early 80s, but these studies have since been revised and improved thanks to our better modelling and computation capabilities.
Hopefully this treaty will help bringing the matter back to the attention of the public opinion. States and governments that continue to pursue nuclear weaponry research and construction, or base their military doctrine on “Nuclear Deterrence”, should be denounced, and their population should apply pressure for these policies to be revised, in the interest of themselves first and foremost, and that of others. These threats are, and will continue to be, very real — unless there is at least a significant reduction of these arsenals to begin with.
“Today, every inhabitant of this planet must contemplate the day when this planet may no longer be habitable. Every man, woman and child lives under a nuclear sword of Damocles, hanging by the slenderest of threads, capable of being cut at any moment by accident or miscalculation or by madness. The weapons of war must be abolished before they abolish us.” (J.F.K — 1961)
You can support this cause action by going to http://nuclearban.org/ and writing to your UN ambassador. Look up the International Campaign to Abolish Nuclear Weapons for more information
-  https://www.washingtonpost.com/news/monkey-cage/wp/2017/07/17/the-u-n-just-passed-a-treaty-outlawing-nuclear-weapons-that-actually-matters/
-  http://www.icanw.org/the-facts/nuclear-arsenals/
-  https://www.armscontrol.org/factsheets/USNuclearModernization
-  http://www.newsweek.com/russia-satan-nuclear-missile-destroy-country-ghost-train-634518
-  http://news.nationalgeographic.com/2016/03/you-and-almost-everyone-you-know-owe-your-life-to-this-man/
-  http://gizmodo.com/the-computer-simulation-that-almost-started-world-war-i-1686123550
-  https://slate.com/news-and-politics/2017/06/able-archer-almost-started-a-nuclear-war-with-russia-in-1983.html
-  http://www.bbc.co.uk/news/world-europe-24280831
-  https://www.youtube.com/watch?v=rq5zv058kTs
-  https://en.wikipedia.org/wiki/List_of_military_nuclear_accidents
-  https://www.economist.com/blogs/graphicdetail/2016/01/safeguarding-nuclear-materials-theft-and-cyber-sabotage
-  https://www.youtube.com/watch?v=1Y1ya-yF35g
-  https://www.youtube.com/watch?v=1QxBJkfYk68
-  https://www.youtube.com/watch?v=VUBY6bMZn8w
-  https://youtu.be/tW7IgKJWtqk?t=9m44s
-  http://climate.envsci.rutgers.edu/pdf/RobockToonSAD.pdf