If the missile gets "intercepted" before it leaves North Korea, and while the populace is tuned to the broadcast, well now wouldn't that be grand!
That is probably the reason there is a time-gap between raising of the flag and state broadcast.
Instead, we will likely wait until we learn another painful lesson of history, because "no one expected" them to be crazy enough to attack us.
If the missile gets "intercepted" before it leaves North Korea, and while the populace is tuned to the broadcast, well now wouldn't that be grand!
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I vote for that one easily.