WARSAW, Poland (AP) — The Russian ambassador to Poland did not show up Monday for a meeting at the Polish Foreign Ministry where he had been summoned because of a Russian cruise missile that violated Polish airspace on the weekend, the Polish ministry’s spokesman said.
“Serving” a diplomatic summons is basically an aggravated appointment negotiation. Nothing wrong with the summoned person having a shower and breakfast and briefing first but it’s very much expected to cancel other appointments if need be, pretty much only excluding doctor’s appointments and stuff. A diplomatic mission has the duty (Article 3 (1) a,c) to represent the sending state and promote friendly relations, it very much stands to reason that if the receiving state is pissed and the sending state’s diplomat is not there to at least waffle and drone then they’re not fulfilling their duty. You can’t just snub the host.