It's true, and it's why Obama never gets credit for the economic crisis that didn't happen.
Not to distract here, but I actually agree with you and werepossum there. If Trump managed to cut a deal with China that is actually somehow beneficial to the US while also getting China to corral NK, then I'd certainly welcome it.
I've no taste for more war or death, but it has only ever been a question of "when" with the DPRNK for the last ~60 years. The real problem is in securing South Korea and Japan from the inevitable fallout and casualties. I don't think this is something that Trump (well, OK: rational humans) can expect China to do unilaterally, without consent and real coordination with SK or Japan.
...which really spells out the absurdity of this speculation: there isn't a single deal Trump can make with China, related to dealing with DPRNK, that doesn't also involve SK and Japan. And, IIRC, SK is in a bit of a political and domestic bug-a-boo with their uh, "government issues" right now.