With its known capacity, Iran cannot make a sudden dash to produce the fuel for a small nuclear arsenal of five implosion-type warheads – the goal Iran set for itself when it began to work on nuclear weapons decades ago. Instead, the main nuclear weapon risk in Iran secret sites, which it has relied on to carry out illicit work in the past. That risk will increase as Iran develops more powerful centrifuges, allowing sites to be smaller and easier to hide. Perfecting such centrifuges is a vital step in the long nuclear game Iran has been playing for decades.