At the end of the Gulf War, international inspectors searching through an Iraqi military site found a U.S. patent that explained how to manufacture nuclear material for an atomic bomb. The patent, U.S. 2,709,222, had been delayed from being granted for years. But in 1955 the U.S. government allowed the patent to issue, believing that its methodology was out of date, and no country would be interested in its contents. Evidently they were wrong.
While a U.S. patent that explains how to make an atomic bomb is unusual, delaying the granting of a patent is something that occurs all the time. Preventing countries from building nuclear missiles is a serious national security issue. For most delays, however, the reasons are more likely to be business-related.
