Editing Permissive action link (section)

=== Critical signal detection ===
[[File:B-61 bomb (DOE).jpg|thumbnail|right|A [[B61 nuclear bomb|B-61]] bomb contains 5,919 parts, including its PAL]]

Nuclear weapons will only respond to a specific arming signal. This is passed to the weapon by a unique signal generator located outside the weapon. This output is specific and well-defined, precluding approximation, emulation, noise, or interference from being accepted as a [[false positive]].<ref name="Peacetime Operations">Donald R. Cotter: "Peacetime Operations: Safety and Security." In: Ashton B. Carter, John D. Steinbruner, Charles A. Zraket (Eds.): ''Managing Nuclear Operations''. Brookings Institution Press, Washington, D.C. 1987, {{ISBN|978-0-8157-1313-5}}.</ref>