问题之四在于，出口管制未能阻止敏感核技术的传播。 这一点尤其源于秘密核网络所采取的复杂而老练的努力，由巴基斯坦核科学家卡迪尔·汗运作的网络便为其中一例。
Fourth, export controls have failed to prevent the spread of sensitive nuclear technology, not least due to the sophisticated efforts of clandestine networks like the one run by Pakistani nuclear scientist A.Q. Khan.