Sam Nunn writes: President Obama’s visit to Hiroshima comes almost 71 years after the conclusion of a world war that was fought and ended with tremendous sacrifice, huge casualties and immense devastation. Today, global nuclear arsenals are capable of destroying not only cities but also civilization itself. Albert Einstein’s prophesy bears repeating: “I do not know how the Third World War will be fought, but I can tell you what they will use in the Fourth — rocks!”

Since the end of World War II, the United States and our allies have relied on the ultimate threat of mutual assured destruction for our security, as the Soviet Union did and Russia does now. Today, with nine nations possessing nuclear arms and terrorists seeking them, this strategy has become increasingly hazardous and decreasingly effective.

Warren Buffett, a man who knows how to calculate risk, has reminded us that if the chance of an event occurring is 10 percent in a given year, and that same risk persists over 50 years, there is a 99.5 percent probability that it will happen during those 50 years. For more than 70 years, the United States and Russia have beaten the odds, avoiding a number of near-disasters. The recent deterioration in relations between the United States and Russia has greatly increased these risks.

The two nations still deploy thousands of nuclear weapons ready to fire on a moment’s notice, risking a catastrophic accident or miscalculation based on a false warning. Cold War dangers compelled dialogue between Washington and Moscow on nuclear security and strategic stability. This dialogue is dangerously absent now, even as our planes and ships have close encounters in Europe and the Middle East. [Continue reading…]