Any broader pre-emption would likely begin with a widespread strike against Pyongyang’s offensive weapons systems (notably artillery batteries arrayed against Seoul, surface-to-surface missiles, and military aircraft). Using cyberattacks to “blind” the North Koreans’ communications networks, undermine their targeting and their access to the GPS, and above all to neutralize their nuclear capability, would be difficult.
All this would require perhaps three or four Navy carrier strike groups — there are only four deployed around the globe right now — significant long-range air support, coordinated missile strikes from South Korean territory, broader deployment of defensive missile technology such as the Thaad system that is (controversially) being deployed in the south now, and a high-end special forces campaign — all of which would be very difficult to execute with tactical surprise. Pyongyang would almost undoubtedly see it coming, and have time to wreak enormous damage.
Soon enough, this would almost certainly lead to engagement on a level of World War II or the Korean War, with hundreds of thousands of casualties. Bad choice.