secret devices

Sometimes political situation change quickly and two countries that today are friends maybe in the near future could be enemies.

Because of that in the past some countries had to fight against airplanes designed and built by their own industries. Example The Canberras of the Fuerza Aerea Argentina during Malvinas war. In the past there was nothing to do against this.
But today technology gives many possibilities.

Is it possible that the countries that produce and sell airplanes, avionics, missiles, radars etc add secretly to this system some kind of controlling device in the hardware or sofware to produce malfunctions in case somebody tries to use this weapons against them?

I suppose it must be easy to “hide” a couple of lines in the fly by wire software making it go crazy when a particular signal is received.

Heechee.