In 1983, the ABC Television Network aired a film, The Day After, which broke all kinds of records for viewership. It’s subject was the aftermath of nuclear war. It’s plot follows a few individuals near Kansas City who survive the initial blast and the next several days after that. The film is fairly well done and so affected Ronald Reagan when he saw it, that he slowed down US nuclear expansion and instead signed some treaties aimed, theoretically, at eventual disarmament.

The backdrops of the film are the familiar landscapes used in post-nuclear war films. However, by the time it was aired, they were already known to be wrong. Scientists interested in mass extinction events, climate change and space had started running simulations on super computers in their spare time to model what might happen if all of the major cities in the west caught on fire all at once. A lot of particulate matter would get into the stratosphere.

Getting particulate matter into the upper atmosphere is now discussed as something we might do on purpose, called geo engineering. These particles would change the colour of the sky, but they also reflect sunlight. This is proposed as an emergency measure against global warming. The reflected sunlight never gets a chance to warm the earth, everything gets slightly colder and darker, but we can burn as much oil as we want.

However, in the case of nuclear war, there would be quite a lot of smoke in the upper atmosphere – enough to make it dark at mid day. And it might stay that way for week or months. Eight days after a full assault, enough sunlight would be blotted out that temperatures would be well below freezing. The cold temperatures and the lack of light would kill most plants within a few weeks – thus depriving animals of food and oxygen.

Fictional depictions of nuclear war, like the film that so effected the president, imagine a war that some might survive, influenced by the testimony of atomic bomb survivors after World War 2. But modern nuclear warheads are so much more powerful than the WWII bombs, that they use those bombs as triggers to start the main explosions. A nuclear war would be an extinction level event on the order of what killed the dinosaurs. Albert Einstein famously said, ‘I do not know with what weapons World War 3 will be fought, but World War 4 will be fought with sticks and stones.’ This may be true, but it won’t be humans holding the sticks and stones millions of years from now. A nuclear war would end human life.

This existential threat was the subject of much activism through the 1980’s, but after the Cold War ended, many people lost interest. The bombs, however, are still around. Russia and China are modernising theirs. Indeed, Putin is rather proud of the updated weapons, warning people not to mess with Russia.

Not to be outdone, the US is doing a major upgrade of its own nuclear arsenal, significantly enhancing it’s ability to end all human life on earth at a cost of $23 billion last year. The project will cost $1 trillion overall. This endeavour – to enhance the ability of the US to end all life on earth several times over – has been ramped up significantly under Obama. Despite this new increase in existential peril, there has not been much in the way of public discussion on the advisability of being able to kill all humans within a few minutes.

If the moderate Nobel Laureate Obama increased nuclear funding by 55% more than George W Bush’s spending, it’s hard to imagine what the more hawkish Clinton might do. This escalation is not only moving away from disarmament, but is also causing instability. By contrast, the prospect of Trump having the launch codes is even more alarming.

Of course, Putin’s remarks are worrying and mark a major revival in nuclear posturing. This kind of rhetoric is, unfortunately, typical for authoritarians. As a part of Bob Altemeyer’s research on this personality type, he had them play a massive board game called The Global Change Game. This didactic game simulates diplomacy and trade with regard to challenges such as climate change, famine and war.

When Altemeyer organised a game with all authoritarian leadership and players, they escalated conflicts until they reached nuclear war. The facilitators then reset them back 50 years previous to give them another chance, but they quickly escalated back to the brink of nuclear war again when they ran out of time to play.

Domestically, the US has always defended it’s ability to kill all of it’s citizens through American Exceptionalism. Other countries might be unstable, but for unexplained reasons, the US is immune to fascism. Alas, it’s becoming increasingly clear that the US is not as exceptional as it might hope. It can happen here and, indeed, might do so within a few months. We are heading for a scenario where the majority of the world’s nuclear arsenal is held by authoritarian leaders. Given that Trump openly admires Putin, would the two operate on a mutual respect level and abstain from murdering all humans, or will they get into a dick measuring contest and kill us all?

Last year, the Bulletin of the Atomic Scientists nudged the Doomsday Clock closer to midnight, citing climate change and ‘modernisation’ programs, warning that we might be entering a new nuclear age. This new age requires new activism. It is vital that, rather than modernise their nukes, the US move as quickly as possible to disarm them. While there is no elected leader who can be trusted with the keys to extinguish all human life, putting them into the hands of fascists is a completely unacceptable risk. Whatever threat that the US would face were it to unilaterally disarm, is minor when compared to the threat of ending all human life.

We cannot continue to rely on the restrain of elected leaders. Even if the US resists fascism in this election, there will always be, like in any country, the risk of electing a government intent on waging war. There is no way to guarantee the safe handling of nuclear weapons, so long as they exist.