Sunday, December 20, 2009

What is an EAM?

This question was recently posted to the UDXF newsgroup:

"I'm new on the list -- do I understand correctly that "EAM" refers to Emergency Action Message? If so, I wonder if all these are related to the weather in the northeast USA."

What is an EAM is a common question that milcom monitors get all the time. EAMs (Emergency Action Messages) have nothing to do with the weather. They are specialized messages transmitted for command and control to various U.S. military units. A basic understanding of what an EAM is can be found at This was written by the dean of USSTRATCOM monitors Jeff Haverlah.

I added additional and new material to Jeff's piece in this month's Monitoring Times magazine in my monthly Milcom column. In my column titled November-Foxtrot-India-India-Four-Sierra: DoD EAMs revisited, I think the best information comes from the top dogs in DoD, the Joint Chiefs of Staff (JCS).

In a JCS instruction 5721.01D dated February 8, 2008 on Nuclear Command, Control, and Communications (NC3) Hybrid Solution (HS), they wrote: "EAMs are highly structured, authenticated messages primarily used in the C2 (Command and Control) of nuclear forces. EAMs are disseminated over numerous survivable and non‑survivable communication systems, including terrestrial and space systems."

In another online publication published in 2008, the Nuclear Matters: A Practical Guide, Chapter 5 had these two statements: “Emergency Action Message – Use Authorization Control. An Emergency Action Message (EAM) is the medium through which actions involving nuclear weapons are authorized. These messages are encrypted and sent to lower‑echelon units for action. The messages have different formats and may require authentication with sealed authentication code cards depending on the intent of the message. “National Military Command and Control System. The Joint Staff Director for Operations (J‑3) operates the C2 system. EAMs are conveyed to the Combatant Commands through secure communications links.”

There is a lot more to this story so if you are a Monitoring Times print or MTXpress subscriber, you can get the rest of the story including frequency and other comm networks (terrestrial , HF and satellite) info on pages 52/53 of your December 2009 Monitoring Times.

And the article mentioned above is not the end of this story. I have more that I plan on publishing in a future Milcom column in MT. You can get more information on MT and MTXpress at or