The massive explosion that rocked Beirut’s port likely killed hundreds, wounded thousands, and rendered 300,000 Lebanese people homeless. But in comparison, the atomic bomb dropped by the United States’s B-29 bombers on Hiroshima and Nagasaki 75 years ago had 15 times that explosion’s destructive power, killed hundreds of thousands of Japanese people, and sickened many more.

After three quarters of a century, the threat of mutually assured destruction engulfing our planet continues to loom over us. President Trump’s nuclear policies — including tearing up international treaties, deploying so-called “low-yield” warheads on submarines, keeping nukes on “hair-trigger alert” to be launched at a moment’s notice, and refusing to rule out new nuclear testing — have only expanded those threats and encouraged proliferation. Trump’s successor will have a huge responsibility to pull us back from the brink and disperse the calamitous mushroom cloud from our horizon.

While the Hiroshima bomb erupted with the energy of 15,000 tons of TNT, many weapons available for launch in the US’s and other country’s arsenals have the explosive power of megatons of TNT. Even the low-yield nukes promoted by the Trump administration aren’t particularly small, and they arguably encourage an arms race and lower the bar toward somebody once again pressing the big red button and unleashing a weapon of mass destruction. Combined with the lack of US support for at least four nuclear treaties, it’s no wonder that leaders of North Korea, Iran, Saudia Arabia, and Turkey want such weapons for themselves.

As Lesley M. M. Blume writes in her new book, Fallout, if it weren’t for journalist John Hersey’s reporting on the horrific devastation and death toll in Hiroshima, Americans might not be aware of the damage the world’s worst weapons have wrought. Another new book, The Beginning or The End, by Greg Mitchell, also demonstrates the attempt by the federal government and Hollywood to cover up the massive death and destruction let loose by the atom bomb. After the war, such an indisputable attack on civilians and civilian infrastructure came to be viewed as a war crime and a crime against humanity.

With the pandemic and climate change, we already have plenty of threats to humanity. 75 years is already too much time to have such horrific weapons in our midst. Trump’s successor will have their work cut out for them to ensure that our era of toying with nuclear disaster soon comes to an end.