That's why there's never been a war between two nuclear-armed countries: everybody is shitting in their pants because of exactly that logic. Presumably we'll find out when the PRC invades Taiwan.
However, if that doesn't end up with a radioactive wasteland, we'll probably find out shortly afterwards what happens when every two-bit drug cartel or extortion mafia can cheaply assassinate anyone, anywhere in the world, with an ambush drone.