Yep, it looks like that. Trump has only two options - backpedal and diplomacy (a.l.a Obama "red lines") or else use conventional force.
This is exactly the same as GWB on 9 September 2001 - only a few months into the Presidency, and a bit of a test. Same with Trump, right now.
Trump would be stupid to use nuclear force pre-emptively, but a forceful show of strength of conventional ordnance (including lots of MOAB's) might well forestall the NORK's nuclear ambitions. There will be many losses to the South Koreans, and US bases in the region. This is a conundrum for the President.