Critics of a deal on Iran's nuclear program, both in the U.S Congress and the Israeli government, need to answer a question: Is there a better alternative?

Even before we know all the details of the agreement hammered out in Geneva this weekend, there's reason to worry about an interim accord that eases a few of the painful economic sanctions imposed on Iran in return for Iran's freezing its drive to develop nuclear weapons. The Iranian regime has been untrustworthy for decades, and the desire for a nuclear bomb is a source of national pride and a security interest.

Yet there is a much different tone since the election of President Hassan Rouhani: The International Atomic Energy Agency reports that Iran has slowed its efforts to convert nuclear power to a bomb. This is progress; it also alters the options, notes Robert Einhorn, a former top State Department policymaker on Iran and nonproliferation.