They were on a diplomatic mission.
I'd say diplomacy is something like sending an ambassador to discuss terms for the placement of radio jammers along our shared border, not violating the integrity of our shared border to drop things on my nation without warning or anything other than the vague mentioning peaceful intentions.
No matter, what's done is done. But next time, try using a bit more diplomacy in your diplomatic invasions. For instance, you could've dropped the jammers on your side of the line, and that would've gone over a lot better on my end.