Kheruchev wanted to improved ties with USA and
China accused Kheruchev of being a traitor.
Kheruchev, pretty much also at urge by USA,
persuaded China not to develop nukes. So China
and USSR ties went sour because USSR tried
to kiss up USA and China wanted to fight USA.
But deteratrating relations eventually pressure
China to defect to USA side. This is the work
of Law of Unintended Consequences (apparently
this law is more reliable even than Newtonian
laws). The same thing will happen here to China-NK
ties.