Hidden inside the network protocol that powers the Internet is a system designed to fight a nuclear war, even if Washington were destroyed by a surprise Soviet attack. Today, it mostly powers cat videos.
This is the system of "precedence," the mechanism that lets the network know that some traffic is more urgent than others. While this may seem like a straightforward idea, the levels of the precedence system -- before the "great renaming" which gave them anodyne names like "AF4/1" -- have a very interesting history indeed.
The first four levels came from US Army standards developed during the Korean War: "routine," "priority," "immediate," and "flash." (With flash priority being for messages that had to be sent in real time -- like "messages recalling or diverting friendly aircraft about to bomb targets unexpectedly occupied by friendly forces," which I think you'll agree is something you want people to know about quickly so they'll STOP SHOOTING AT YOU)
The fifth level, "flash override," was developed in the late 1950's -- a special precedence level which only the President and Secretary of Defense (or their deputies, if they were killed) were allowed to use, intended to let them override all other traffic and give the orders to end the world.
On top of this is a sixth
level, "CRITIC/ECP." This level was almost entirely forgotten: it was introduced between 1958 and 1963, and then promptly ignored by every generation of documentation afterwards. It remained not quite secret, but never really discussed; a drastic highest priority never used, until mathematical necessity forced its introduction into the Internet Protocol./
The story below is a dive into the rabbit-hole of Cold War planning: how the system designed in secret for the Air Force ultimately ended up powering realtime games and video chat.The next time you’re streaming an old X-Files episode on Netflix that you’re actually using a mechanism designed to ensure that nuclear war could be reliably fought, even if it had to be done from a modified Boeing 707 after Washington was destroyed. The truth, in this case, is in there.
(Footnote for interested readers: This is, I believe, the first time the entire story, from the military side through to the network side, has been in one place. Many thanks to +Lauren Weinstein
, among others, for helping me trace the various threads that led to this.)