There are far better ways to drum up support for an invasion of North Korea than a false-flag hacking of an entertainment company. All you'd really have to do is wait a little while until they test another nuclear bomb or shell South Korea again or sink another South Korean ship or anything of the sort, and then take a hard line response instead of the standard "if we ignore them maybe they'll go away" response. The idea that this was drummed up to start a war makes no sense to me.