SK does not have the same type of halo type system as Israel. Basically, they have to depend on THAAD, which works well for singular missile attacks, but not so much for a barrage of artillery. NK would for a certainty unload on Seoul if we made a preemptive attack.
The options are not good and our "leadership" is useless, to put it mildly.
Also, China will be of no help. The Chinese use NK as a buffer to limit US influence in the region, despite what they officially state. That will not change. They are the ultimate pragmatists, and see this crisis to their advantage, long-term.