North Korea threatened to shoot down U.S. reconnaissance planes flying off its east coast this week, and while it may seem like empty bluster, a look at history shows that it has taken down American aircraft before — and in the process provoked Washington to even consider nuclear strikes.

On April 15, 1969, a North Korean MiG-21 opened fire on a U.S. Navy EC-121 reconnaissance plane off the east coast of the peninsula, resulting in the deaths of 31 Americans.

Pyongyang maintainedthat the plane had infiltrated “deep into the territorial air” of the DPRK, even though it appears to