They filled reserves last year November or something. I remember reading up on it. At the time I thought they were ready (gold, oil reserved) and we're building landing ships and barges. 

Then Venezuela happened and then Iran. ..my thinking is that both attacks by the USA is intended to pull China into the fast track, forced to either do something or grind to a halt (as long as the oil is cut off air diverted. )

Most of Iranian oil heads to China so imo this was known six months prior. 

We'll see how long that reserve lasts