I suspect your comment may have been intended as a joke but airborne leaflet dropping has been a thing for at least 150 years[0] and the Voice of America sent broadcast messages deep into the Soviet Union during the Cold War. Governments speaking directly to an opposing population is neither new nor classified as an act of war (however much it may piss off the receiving government).

[0] https://en.m.wikipedia.org/wiki/Airborne_leaflet_propaganda