Should the United States decide to send in military forces to secure Iran’s uranium stockpile, experts and former U.S. government officials say it would be a complex, risky and lengthy operation, fraught with radiation and chemical dangers. Another option would be a negotiated settlement allowing the material to be secured without using force. According to the International Atomic Energy Agency, Iran has 440.9 kilograms of uranium enriched to 60% purity. IAEA head Rafael Grossi says that could allow Iran to build as many as 10 nuclear bombs, should it decide to weaponize its program. Iran long has insisted its program is peaceful, but the IAEA and Western nations say Tehran had a nuclear weapons program until 2003.