One of the most iconic and important U.S. defense facilities used during the Cold War is being brought back online: Cheyenne Mountain.

First built in the 1960s, Cheyenne Mountain was established as a critical communications center deep inside the Rocky Mountains in Colorado. Its location was selected with the belief that Air Force personnel stationed inside Cheyenne Mountain would survive a nuclear attack from the Soviet Union.

The vast complex, which includes 15 three-story buildings as well as water and power supplies, provided both early-warning monitoring of a Soviet attack and communications to help launch a U.S. nuclear strike of its own. But by last decade, the Air Force had largely pulled out of Cheyenne Mountain, believing the threat of a nuclear attack was no longer a serious concern.

Military officials have not explained why they started reinvesting in and upgrading Cheyenne Mountain about two years ago. And in March 2015, the Air Force awarded defense contractor Raytheon a $700 million contract to install new equipment inside the mountainous operations center.

“[T]here is a lot of movement to put capability into Cheyenne Mountain and to be able to communicate in there,” Adm. William Gortney, commander of U.S. Northern Command and of North American Aerospace Defense Command (NORAD), told reporters at the Pentagon.

Gortney did say that some of the work is intended to better shield Cheyenne Mountain’s communications from electromagnetic pulses, or EMPs, which can disrupt all electronic signals across a wide area.

The mention of EMPs by NORAD’s commander may be very telling. NORAD itself is a remnant of the Cold War — U.S. defense planners frequently discussed EMPs decades ago, when there were fears that the Soviets would deliberately explode nuclear warheads high above the country in an effort to fry American communications. Does the revamping of Cheyenne Mountain and guarding against EMPs signal a new worry within the Pentagon that it once again must plan against a foreign power armed with ballistic nuclear missiles?

-Noel Brinkerhoff

To Learn More:

Pentagon Moves More Communications Gear into Cheyenne Mountain (by Marcus Weisgerber, Defense One)

Why Is the US Military Moving Back into 'Stargate' Base Deep under the Rocky Mountains a Decade after It Was Abandoned? (by James Nye, Daily Mail)

Contracts (U.S. Department of Defense/Air Force)