President Obama is already committed to negotiating cuts in tactical nukes. And he may have some new allies: Republicans who pushed through a side resolution to the New Start treaty requiring negotiations on tactical weapons within a year. If they meant what they said — and weren’t just trying to kill New Start — they need to support the president in any negotiations and commit to swift ratification of a treaty…

The two sides cannot stop there. They also need to reduce their number of stored warheads — their “hedge.” Russia and the United States are each estimated to have around 2,000 stored weapons. Some spares are needed as replacements in case of catastrophic failure in deployed warheads or cheating by the other side, but these huge reserves are far more than necessary…

We also strongly urge President Obama to press Congress to ratify the Comprehensive Test Ban Treaty, signed by President Bill Clinton in 1996. It is nearly impossible for countries to build weapons without testing, so the treaty is a powerful tool for curbing proliferation. But it cannot come into force without ratification by the United States and a handful of other countries.