History Main / ThisIsNotADrill

** The classic historical example of its use is in the alarm bulletin sent out by telegraph on December 7, 1941: "[[ThisMeansWar AIR RAID]] [[UsefulNotes/WorldWarII PEARL HARBOR]] [[https://en.wikipedia.org/wiki/Attack_on_Pearl_Harbor#cite_note-120 THIS IS NOT DRILL]]".

* [=NATO=] tried extremely hard to play this trope as straight as possible in 1983 during the Able Archer exercises, which were meant to test the robustness of communications and command and control systems in the events leading up to and through the initiation of a nuclear war. Realizing that Soviet signal intelligence would be listening in to all messages, they broadcasted the exercise messages in the clear with EXERCISEEXERCISEEXERCISE as a header. Unfortunately, the Soviet leadership was WrongGenreSavvy and suspected that the messages were a ruse for a surprise attack. [[note]]In hindsight, November 1983 was a particularly poor choice of timing for a nuclear exercise of any kind. Not only was the physical and mental health of Soviet leader Yuri Andropov dangerously precarious (leading to potential miscalculations and paranoia on Andropov's part), but the Soviets were already riled and wary after Reagan's "Evil Empire" speech. And after escalations on both sides (such as Reagan's "playing chicken" with the Soviets in terms of more aggressive drills and reconnaissance flights, which ended badly after [=KAL-007=] was mistaken for an American spy plane and was shot down with the loss of nearly 300 lives over the Sea of Japan), Soviet nerves were raw, and they were ready to believe the worst. Finally, the Soviet "[=RYaN=]" project, which was collecting data points to fit a pre-conceived notion that the [=US=] was plotting a sneak nuclear attack on the Soviet Union -- spoiler alert: it wasn't -- had just about collected enough evidence to sound the alarm.[[/note]]Fortunately for ''everyone'', the Soviets did come to their senses in the nick of time and realized that the exercise was indeed an exercise.

* In an episode of ''Series/DiagnosisMurder'', the hospital staff stage a fake emergency to demonstrate their preparedness in the event of an emergency, only for 1) one of their patients to turn up murdered and 2) a tunnel collapse resulting in the ER being flooded with real casualties. For bonus points, several cast members of both the series ''Series/{{MASH}}'' and the movie ''Film/{{MASH}}'' played supporting roles in the episode.