The scenes where David Soul (Col. Caffey) is shown his quarters, where his office was in Alaska and the hall where the US President (Rock Hudson) and the Russian Premire (Brian Keith) meet were all filmed at the former Naval and Marine Corps Reserve Center, Encino, CA. The address is 6336 Balboa Blvd, Encino, CA. A lot of the extras in Army uniforms were actually US Navy personnel. Notice the blue doors and door jams in the office scene.
The series takes place in 1987.
The meeting between the American and Russian presidents in a Reykjavik school gym predates the very similar meeting between Reagan and Gorbachev just four years later ("The Reykjavik Summit"), though both likely drew some inspiration from the Fischer - Spassky chess championship held there in 1972 during the peak years of detente, given the geographical half way location and historically remaining neutral ground.