In our town, we had the warmth of family life, the deep human bonds of community, festivals heralding each season, traditional culture and buildings passed down through history, as well as riversides where children played.

At 8:15 a.m., Aug. 6, 1945, all of that was destroyed by a single atomic bomb. Below the mushroom cloud, a charred mother and child embraced, countless corpses floated in rivers, and buildings burned to the ground. Tens of thousands were burned in those flames. By year’s end, 140,000 irreplaceable lives had been taken, that number including Koreans, Chinese, Southeast Asians, and American prisoners of war.

Those who managed to survive, their lives grotesquely distorted, were left to suffer serious physical and emotional aftereffects compounded by discrimination and prejudice. Children stole or fought routinely to survive. A young boy rendered an A-bomb orphan still lives alone; a wife was divorced when her exposure was discovered. The suffering continues.

“Madotekure!” This is the heartbroken cry of hibakusha who want Hiroshima — their hometown, their families, their own minds and bodies — put back the way it was.

One hundred years after opening as the Hiroshima Prefectural Commercial Exhibition Hall and 70 years after the atomic bombing, the A-bomb Dome still watches over Hiroshima. In front of this witness to history, I want us all, once again, to face squarely what the A-bomb did and embrace fully the spirit of the hibakusha.

Meanwhile, our world still bristles with more than 15,000 nuclear weapons, and policymakers in the nuclear-armed states remain trapped in provincial thinking, repeating by word and deed their nuclear intimidation. We now know about the many incidents and accidents that have taken us to the brink of nuclear war or nuclear explosions. Today, we worry as well about nuclear terrorism.

As long as nuclear weapons exist, anyone could become a hibakusha at any time. If that happens, the damage will reach indiscriminately beyond national borders. People of the world, please listen carefully to the words of the hibakusha and, profoundly accepting the spirit of Hiroshima, contemplate the nuclear problem as your own.

A woman who was 16 at the time appeals: “Expanding ever wider the circle of harmony that includes your family, friends and neighbors links directly to world peace. Empathy, kindness, solidarity — these are not just intellectual concepts; we have to feel them in our bones.” A man who was 12 emphasizes: “War means tragedy for adults and children alike. Empathy, caring, loving others and oneself — this is where peace comes from.”

These heartrending messages, forged in a cauldron of suffering and sorrow, transcend hatred and rejection. Their spirit is generosity and love for humanity; their focus is the future of humankind.

Human beings transcend differences of nationality, race, religion and language to live out our one-time-only lives on the planet we share. To coexist we must abolish the absolute evil and ultimate inhumanity that is nuclear weapons. Now is the time to start taking action. Young people are already starting petition drives, posting messages, organizing marches and launching a variety of efforts. Let’s all work together to build an enormous groundswell.

In this milestone 70th year, the average hibakusha is now over 80 years old. The city of Hiroshima will work even harder to preserve the facts of the bombing, disseminate them to the world and convey them to coming generations. At the same time, as president of Mayors for Peace, now with more than 6,700 member cities, Hiroshima will act with determination, doing everything in our power to accelerate the international trend toward negotiations for a nuclear weapons convention and abolition of nuclear weapons by 2020.

Is it not the policymakers’ proper role to pursue happiness for their own people based on generosity and love of humanity? Policymakers meeting tirelessly to talk — this is the first step toward nuclear weapons abolition. The next step is to create, through the trust thus won, broadly versatile security systems that do not depend on military might. Working with patience and perseverance to achieve those systems will be vital, and will require that we promote throughout the world the path to true peace revealed by the pacifism of the Japanese Constitution.

The summit meeting to be held in Japan’s Ise-Shima next year and the foreign ministers’ meeting to be held in Hiroshima prior to that summit are perfect opportunities to deliver a message about the abolition of nuclear weapons. President Obama and other policymakers, please come to the A-bombed cities, hear the hibakusha with your own ears, and encounter the reality of the atomic bombings. Surely, you will be impelled to start discussing a legal framework, including a nuclear weapons convention.

We call on the Japanese government, in its role as bridge between the nuclear- and non-nuclear-weapon states, to guide all states toward these discussions, and we offer Hiroshima as the venue for dialogue and outreach. In addition, we ask that greater compassion for our elderly hibakusha and the many others who now suffer the effects of radiation be expressed through stronger support measures. In particular, we demand expansion of the “black rain areas.”

Offering our heartfelt prayers for the peaceful repose of the A-bomb victims, we express as well our gratitude to the hibakusha and all our predecessors who worked so hard throughout their lives to rebuild Hiroshima and abolish nuclear weapons. Finally, we appeal to the people of the world: renew your determination. Let us work together with all our might for the abolition of nuclear weapons and the realization of lasting world peace.