The fragile Israel-Iran ceasefire and ongoing Ukraine war have reignited global focus on nuclear weapons. Recent U.S. threats against Iran’s nuclear sites, along with SIPRI’s warning of a new nuclear arms race, highlight expanding arsenals worldwide. With over 12,000 warheads globally—mostly held by the U.S. and Russia—and declining transparency, experts warn current deterrence strategies may fail. Rising tensions risk reversing disarmament gains, potentially pushing the world into a more dangerous era where mistakes could have catastrophic consequences.