In the opening scenes when the missile officers are getting their sidearms from Keegan, it shows Keegan wearing a missile badge (known as a "pocket rocket") on his uniform and in a later scene he is wearing a security police badge on the same pocket. See more
Launch Officer #1
[looking at a large satellite image screen
Looks like a satellite re-entry to me.
Launch Officer #2
[after checking data on computer
Negative on satellite...
[Soviet ICBM missile launch indications appear on a large computer screen, alarm sounds
Blue Square One, Blue Square One, Blue Square One. Alpha, Tango, Foxtrot, Sierra, Delta. Two. Omega, Zebra, Six, One. Authentication Sierra Alpha.
Launch Officer #3