It's so obvious this is the next stage of conflict. China could have thousands of these sleeper drones in the US. To preempt before a real conflict, it could simultaneously take out most of the heads of state, causing chaos.
Why is China your example and not X? There are other countries that use killer drones, do secret killing and kidnapping operations on other countries territories etc.
I have the impression that a few years back you would have said Russia, then N Coreea and today China, like the big bad enemy is changing each few years depending on what politics need.
The good old fashion alternative is just a gunman. It's more plausibly deniable - e.g. still nobody is exactly sure what was going on with Lee Harvey Oswold and Jack Ruby - and it doesn't put the targeted country immediately on a war footing.
Gee, chaos, that would be terrible.
Yeah, and 911 was an inside job!
EDIT: If you think China has thousands of sleeper drones in the US you are on par with people who think 911 was an inside job, end of story. Down vote all you want but be sure to don your tin foil hats afterwards.