Why would you need a specific law to shoot down drones in your own territorial airspace? This is something any nation should do, ie Chinese balloon incursions into NA airspace. Handle it and fuck the offending nation if they don’t like it!
You see, peace in Europe is only maintained through the ability (or illusion thereof) of russia being able to invade and otherwise exert influence over former soviet and warsaw pact states at any point in time with little resistance.
The moment there is the credible threat of resistance, it is a clear provocation and justifies a response, possibly an invasion.
I trust I cleared that up for you.
edit: The sad part is, this is similar to US and Chinese policy. World and regional power politics is closer to schoolyard bully behaviour than we’d like. Vote for your favourite bully today!
Probably because shooting down stuff that moves in your airspace puts commercial aviation at risk. So I’ll guess they need to think about when it is legally allowed so that IF something horrible happens, the air defense operators are not on the hook
