Even the smallest possible military strike against North Korea – one that would disable enough artillery to prevent a catastrophic retaliation against South Korea – will cost well into the tens of millions of dollars. What else might we do with that amount of money to undermine Kim Jong Un? How about air drop tons of cheap internet devices, extended batteries, solar and hand chargers, and secure burst-WAN equipment (using tech that North Korean police can’t easily detect when in use), combined with reverse spy-trawlers – “ISP ships”, balloons, and satellites – to start allowing North Koreans to discover the outside world, unfiltered.
It would be a much better use of the money, and Samsung is right there in South Korea ready and able to produce devices. Consider it an economic stimulus. To further protect citizens accessing the internet, decoy devices could be periodically dropped that simulate the same type of emissions the internet devices emit.
If North Korea will ever get on a path to a Kim Jong-less future, there will have to be some degree of civil war and blood-shed – the regime supporters and those in (relative) power will not give it up without a fight to the death. But indiscriminately killing a bunch of North Korean citizens would be an extraordinarily bad way to try to kick that process off. We’d be smarter to empower the potential dissidents and undermine support for Un as much as possible, first.