In the United States military's
strategic nuclear weapon
A strategic nuclear weapon (SNW) refers to a nuclear weapon that is designed to be used on targets often in settled territory far from the battlefield as part of a strategic plan, such as military bases, military command centers, arms industries, ...
nuclear command and control
Nuclear command and control (NC2) is the command and control of nuclear weapons. The U. S. military's ''Nuclear Matters Handbook 2015'' defined it as the "activities, processes, and procedures performed by appropriate military commanders and sup ...
(NC2) system, an Emergency Action Message (EAM) is a preformatted message that directs nuclear-capable forces to execute specific Major Attack Options (MAOs) or Limited Attack Options (LAOs) in a
nuclear war
Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear w ...
. They are the military commands that the US military chain of command would use to launch a nuclear strike. Individual countries or specific regions may be included or withheld in the EAM, as specified in the
Single Integrated Operational Plan
The Single Integrated Operational Plan (SIOP) was the United States' general plan for nuclear war from 1961 to 2003. The SIOP gave the President of the United States a range of targeting options, and described launch procedures and target sets a ...
(SIOP). The SIOP was updated annually until February 2003, when it was replaced by
Operations Plan
''Operations plan'' (in Spanish, "Plan de Operaciones") is a secret document attributed to Mariano Moreno, that set harsh ways for the Primera Junta, the first ''de facto'' independent government of Argentina in the 19th century, to achieve its g ...
(OPLAN) 8044. Since July 2012, the US nuclear war plan has been OPLAN 8010-12, ''Strategic Deterrence and Force Employment''.
Overview
EAMs use
cryptographic protocol
A security protocol (cryptographic protocol or encryption protocol) is an abstract or concrete protocol that performs a security-related function and applies cryptographic methods, often as sequences of cryptographic primitives. A protocol describe ...
s (including such methods as
digital signature
A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created b ...
s) to authenticate the messages,
thereby ensuring that they cannot be forged or altered.
In the United States, the EAM will be issued from the
National Military Command Center
The National Military Command Center (NMCC) is a Pentagon command and communications center for the National Command Authority (i.e., the President of the United States and the United States Secretary of Defense). Maintained by the Department o ...
(NMCC) at
the Pentagon
The Pentagon is the headquarters building of the United States Department of Defense. It was constructed on an accelerated schedule during World War II. As a symbol of the U.S. military, the phrase ''The Pentagon'' is often used as a metony ...
or, if it has been destroyed by an enemy first strike, by the
Alternate National Military Command Center - Site R at
Raven Rock, Pennsylvania
The Raven Rock Mountain Complex (RRMC), also known as Site R, is a U.S. military installation with an underground nuclear bunker near Blue Ridge Summit, Pennsylvania, at Raven Rock Mountain that has been called an "underground Pentagon". The bu ...
or by the
U.S. Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...
E-4B Nightwatch aircraft/
U.S. Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...
E-6A Mercury aircraft (TACAMO).
The messages are sent in digital format to nuclear-capable major commands. The messages are then relayed to aircraft that are on alert by the
U.S. Strategic Command at
Offutt Air Force Base
Offutt Air Force Base is a U.S. Air Force base south of Omaha, adjacent to Bellevue in Sarpy County, Nebraska. It is the headquarters of the U.S. Strategic Command (USSTRATCOM), the 557th Weather Wing, and the 55th Wing (55 WG) of the Air ...
in
Omaha, Nebraska
Omaha ( ) is the largest city in the U.S. state of Nebraska and the county seat of Douglas County. Omaha is in the Midwestern United States on the Missouri River, about north of the mouth of the Platte River. The nation's 39th-largest cit ...
, via
single-sideband modulation
In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude modul ...
radio transmitters of the
High Frequency Global Communications System The High Frequency Global Communications System (HFGCS) is a network of single sideband shortwave transmitters of the United States Air Force which is used to communicate with aircraft in flight, ground stations and some United States Navy surface ...
(formerly known as the Global High Frequency Service). The EAM is relayed to
missile-firing nuclear submarines via special transmitters designed for
communication with submarines
Communication with submarines is a field within military communications that presents technical challenges and requires specialized technology. Because radio waves do not travel well through good electrical conductors like salt water, submerged ...
. The transmitters include those designed to operate at
Very Low Frequency
Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave a ...
(VLF). The submarines pick up the message via special antennas. Nuclear-capable forces will then be expected to carry out an EAM without fail. Crewed bombers may be recalled, but missiles fired from land-based silos or from submarines cannot be recalled.
Skyking messages are also read on the same network as EAMs, also known as "Foxtrot Broadcasts". These messages will interrupt an EAM if needed to be read. They contain a higher priority and time-sensitive code for orders that need immediate attention.
In popular culture
The EAM system was featured extensively and used as one of the primary plot devices in the feature film ''
Crimson Tide''.
See also
*
Gold Codes
The Gold Codes are the launch codes for nuclear weapons provided to the President of the United States in their role as commander-in-chief of the armed forces. In conjunction with the nuclear football, the Gold Codes allow the president to autho ...
*
Nuclear football
The nuclear football (also known as the atomic football, the president's emergency satchel, the Presidential Emergency Satchel, the button, the black box, or just the football) is a briefcase, the contents of which are to be used by the preside ...
*
Emergency Action Notification
An Emergency Action Notification ( SAME code: EAN) is the national activation of the Emergency Alert System (EAS) and is used to alert the residents of the United States of a national or global emergency such as a nuclear war or any other mass ...
References
Further reading
*
*
* (FOIA Release, February 1986)
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Nuclear warfare
United States nuclear command and control