In a statement read at the Global Zero [2] summit in Paris today, President Obama repeated his commitment to the ambitious nonproliferation goals he set out in his Prague speech [3]. "At our Nuclear Security Summit in April we will rally nations behind the goal of securing the world’s vulnerable nuclear materials in four years," Obama said. "We will strengthen the Nuclear Nonproliferation Treaty and work with allies and partners to ensure that the rights and responsibilities of every nation are enforced. We will seek to ratify the Comprehensive Test Ban Treaty and negotiate a Fissile Material Cutoff Treaty. And our Nuclear Posture Review will reduce role and number of nuclear weapons in our national security strategy."   He added, "Make no mistake, this will be hard. Progress will be neither quick nor easy. Rather than fixed deadlines, we will work toward reductions that are historic yet realistic, ambitious yet achievable. And as I’ve said, our ultimate goal may not be realized in our lifetimes."  (Stay tuned to additional news from the Ploughshares-funded Global Zero conference from Joe Cirincione [4] and Naila Bolus [5], who are in participating in the discussions in Paris.)