Major changes must be made if U.S. nuclear war plans are to conform to the principles of just war doctrine and the law of armed conflict, declares Stanford University's Scott Sagan. He proposes a new doctrine: "the nuclear necessity principle." In sum, the U.S. will not use nuclear weapons against any target that could be reliably destroyed by conventional means.

The threat of a nuclear nightmare is still real, says Joe Cirincione. With unsecured stockpiles in Russia, the ever-present threat of terrorists getting hold of a bomb, and the possibility of a nuclear Iran, America and the world need to pay attention to this potentially catastrophic issue.

The threat of a nuclear nightmare is still real, says Joe Cirincione. With unsecured stockpiles in Russia, the ever-present threat of terrorists getting hold of a bomb, and the possibility of a nuclear Iran, America and the world need to pay attention to this potentially catastrophic issue.

What if everything we believe about nuclear weapons is wrong? "Reexamine the facts and you'll see that the arguments for nuclear weapons aren't powerful; they're preposterous. They are an unpersuasive collection of wishful thinking held together by nothing more than fear and rationalization."

In the Cold War, the path to nuclear war always led through Moscow and Washington. In the second nuclear age the triggers to nuclear war are in Tel Aviv, Islamabad, Pyongyang, and in the future possibly Tehran, and possibly in other places too, because you can start a nuclear war even if you don't have nuclear weapons.

In the Cold War, the path to nuclear war always led through Moscow and Washington. In the second nuclear age the triggers to nuclear war are in Tel Aviv, Islamabad, Pyongyang, and in the future possibly Tehran, and possibly in other places too, because you can start a nuclear war even if you don't have nuclear weapons.

Doctors Roald Sagdeev and Frank von Hippel have collaborated for decades on nuclear arms control and nonproliferation between the U.S. and the USSR. They discuss their work and their insights for the future arms control agenda.

Doctors Roald Sagdeev and Frank von Hippel have collaborated for decades on nuclear arms control and nonproliferation between the U.S. and the USSR. They discuss their work and their insights for the future arms control agenda.

Jayantha Dhanapala, former under-secretary-general for Disarmament Affairs at the UN, gives his views on "getting to zero" on nuclear weapons.

Jayantha Dhanapala, former under-secretary-general for Disarmament Affairs at the UN, gives his views on "getting to zero" on nuclear weapons.