Here are 10 lessons that I learned about nuclear weapons in the process of working for their abolition for the past four decades. I wish I could share these lessons with every citizen of the planet, all of whom are endangered by these weapons.

The effects of nuclear weapons cannot be contained in space or time. Radiation from a nuclear detonation is carried by the wind and cannot be stopped at national borders, with or without border checkpoints. Radioactive materials also have long lives. Plutonium-239, for example, has a half-life of 24,000 years and will remain deadly if inhaled for the next 240,000 years. Nuclear weapons have made possible omnicide, the death of all. Omnicide is a 20th-century concept created by philosopher John Somerville. It is the logical extension of suicide, homicide, genocide. Although it is a concept too final to even imagine, it must be taken seriously. The survivors of the atomic bombings of Hiroshima and Nagasaki are the ambassadors of the nuclear age, having witnessed first-hand the horror of nuclear weapons use and not wanting their past to become anyone else’s future. Many survivors, known as hibakusha, have made it their life’s work to speak out to educate others and to rid the world of nuclear weapons. Nuclear deterrence does not provide physical protection against nuclear weapons — it provides only a false sense of security and the possibility of retaliation and vengeance. Reliance on nuclear deterrence opens the door to omnicide. Nine countries with nuclear weapons are playing Nuclear roulette with the human future. Nuclear weapons are like having grenades pointed at the heart of humanity, putting everything we love and treasure at risk. With Nuclear roulette the odds are not with humanity. Einstein warned: “The unleashed power of the atom has changed everything save our modes of thinking, and we thus drift toward unparalleled catastrophe.” For ourselves, our countries and our planet, we must change our modes of thinking and end the widespread ignorance and apathy surrounding nuclear weapons. We must rid the world of nuclear weapons before they rid the world of us. Nuclear weapons are an absolute and ultimate evil. Their only purpose is to kill indiscriminately — women, men and children, as well as other forms of complex life. There are many ways a nuclear war could begin: by malice, madness, mistake, miscalculation or manipulation (hacking). That we have not yet had a nuclear war is more from good fortune than good planning. We have come chillingly close on numerous occasions. Nuclear weapons make us all reliant for our lives and futures on the sanity and wisdom of a small number of national leaders. It is far too much power to put in the hands of any leader. We must speak out, join together and demand that these weapons be abolished before they abolish us. The choice between two memes of the 20th century will determine whether humankind survives the 21st: the image of the mushroom cloud, and the image of the earth from outer space. The first is an image of death and destruction, while the second is an image of the fragility of our planetary home, the only place we know of in the universe where life exists. The choice should be clear, and it calls out to us to choose peace, not war; survival, not devastation; hope, not despair; and engagement to save our planet and the precious gift of life it harbors.