On August 6, 1945, the day Hiroshima was bombed with an atomic weapon, humanity walked through a door into an era in which our own annihilation as a species became possible.

The bombing was a triumph of destructive technology. It sent a message that all cities would become vulnerable to instant devastation. And indeed, over the decades that followed Hiroshima, all cities did become vulnerable to annihilation.

Nuclear “weapons” are not weapons in the traditional sense of being used to injure or kill enemy forces. Rather, they are devices capable of inflicting massive destruction on population centers, and taking countless innocent lives. In this sense, they are weapons of terrorists.

The countries that possess nuclear weapons and base their security on the threat of their use do not ordinarily think of themselves as terrorist states, but by any reasonable definition of terrorism they are. They are states that threaten massive retaliation against civilian populations, in violation of the rules and norms of international law.

There is only one way to assure a human future in which cities are not held hostage to the fate of Hiroshima and Nagasaki, and that is by developing new methods of cooperation among nations and peoples. The logical place for this cooperation to take place is in the United Nations, the organization of the world’s nations created with the strong support and leadership of the United States.

Franklin Roosevelt viewed the United Nations as essential if mankind were to avoid the “scourge of war” which twice in the first half of the 20th century had caused “untold sorrow.” After Roosevelt’s death in April1945, Harry Truman assured that his predecessor’s dream became a reality.

In the 21st century, nuclear and other weapons of mass destruction can cause even worse consequences than “untold sorrow.” These weapons can cause unimaginable and unalterable silence; they are capable of bringing history to an end by bringing humankind and most other forms of life to an end. We should never lose sight of this. We should never become too comfortable or complacent with these destructive devices holding the potential for our shared demise.

Missile defenses will not protect us. Such plans offer only comforting illusions. Nor will the threat of retaliation protect us. There will always be some who are too crazed or unreasonable to be deterred by threat of retaliation. There will always be the possibility of human error that leads us stumbling into a disastrous war.

The only way out is to end the nuclear era by agreeing to the phased elimination of nuclear and other weapons of mass destruction. Such agreements must be solidly built with inspections and other means of verification. Such agreements among nations are possible, but they require leadership and particularly leadership from the United States, the world’s most powerful nation.

We live in a nation in which government is “of the people, by the people and for the people.” Therefore, we, the people, can prevail if we make our voices heard. If the people of this country speak out with a strong voice, the United States could reassume leadership in the United Nations. We could help to build a world free of the threat of all weapons of mass destruction.

This is a future worth believing in and fighting for. And the effort must begin with each of us. As Albert Camus, the great French writer and philosopher, said in reaction to learning of the bombing of Hiroshima, “Peace is the only battle worth waging. It is no longer a prayer, but an order which must rise up from peoples to their governments – the order to choose finally between hell and reason.”

*David Krieger is president of the Nuclear Age Peace Foundation.