Here is a photo you have seen before. In all likelihood it is the most iconic image of the Nuclear Age: "Baker" test of Operation Crossroads, Bikini Atoll of the Marshall Islands, 1946.

I want to draw your attention to something I bet you have never noticed in this photo before, as many times as you've seen it. See this black smudge on the nearly 1/2 mile high column of water thrown up by the underwater detonation?

That's the USS Arkansas. That's a 562 foot long, 26,000 ton battleship.

Look at the full sized photo and use that as a point of reference for scale. The giant destroyer was found later upside down in the lagoon with the side facing the blast crumpled like a soda can. The site also became unfathomably radioactive. Pieces of crushed coral and metallic sodium from the seawater were irradiated and flung about the Atoll. 15,000 Navy men were rushed in to scrub down the ships of the ghost fleet that had been set up as target practice and to bury some of the more energetic debris. No statistics on the amount of radiation those people absorbed (or what it did to them in the long run) are available.

I point this out to emphasize something that has been forgotten since the end of the Cold War during which nuclear weapons were something people thought about regularly. They used to be very real, not abstract, and now the opposite is true. Nuclear weapons are powerful. Staggeringly powerful. They are, in the parlance of The Kids, not fucking around. Crossroads "Baker," the subject of this infamous photo, was a replica of the nuclear device detonated over Nagasaki, which in turn was a replica of the "Trinity" bomb exploded in New Mexico as the first even nuclear device. In other words, the bomb that caused what you see in this photo was a small one. Primitive. Simple. By modern standards what you see here is puny. But it rendered the area uninhabitable for seven decades and tossed around some of the largest objects humans know how to make.

We live in a world in which people stopped grappling with the reality of nuclear war so long ago that we have whole generations that don't fully understand its implications, and older generations who used to understand it but have let the memories fade. It seems inevitable these days that someone – India, Pakistan, North Korea, or very possibly the US – will blow one up if for no reason other than that the world hasn't seen a mushroom cloud for decades and, well, let's just see if it's really as big a deal as people used to think it was. World leaders ("leaders") like Putin, Kim, and Trump refer to nuclear weapons in terms that show no understanding of or respect for their power. To threaten to use nuclear weapons at the drop of a hat is to admit that you have only the vaguest idea of the effects and consequences of doing so.

Why so many nations simultaneously find themselves led by someone who doesn't quite get it is above my pay grade to figure out. Maybe we've all lost our collective minds. Maybe nukes simply aren't the big political issue they used to be, so absenting them from our consciousness leaves a lot of people unaware of the gravity of the problem. Or maybe we are all fated to relive our worst decisions every time a tragedy recedes far enough into the past for people to start thinking "I mean, it can't really be THAT bad…let's just try one and see."

The first lesson we will learn if we go down that road is that a nuclear weapon that can pick up a battleship and fling it like a toy is only a fraction as powerful as the arsenal available today. Thermonuclear weapons – which were only an idea at the time this photo was taken – are almost limitless in their power and radioactive fallout potential. Politicians the world over used to recognize that nuclear weapons are not a thing to be trifled with; now, the more we talk about them casually or in a way that trivializes them brings us closer and closer to the point at which the useful fear of them is overcome by the impulsiveness and anger of the people who control them.

I have a bad feeling about it. All of it.