The E-6B model deployed in October 1998 has the ability to remotely control Minuteman ICBMs using the Airborne Launch Control System. The E-6B replaced Air Force EC-135Cs in the "Looking Glass" role, providing command and control of U.S. nuclear forces should ground-based control become inoperable.
https://www.pbs.org/video/1404-restoring-looking-glass-u9q4ab/
1404: Restoring the Looking Glass
After 6 years and more than 32,000 volunteer hours, the Boeing EC-135 “Looking Glass” has been restored to its former glory. At the height of the Cold War, this aircraft was part of Strategic Air Command’s “Operation Looking Glass,” which mirrored the nuclear command control at Offutt Air Force Base. Now, this historic aircraft is on display at the Strategic Air and Space Museum in Ashland.