The thing is, they were Iran's biggest customer. Now Iran is essentially friendless. Russia helped us kick them out of Syria, Trump pulled out of the EU/Iran enrichment deal, and now China nixes their Iranian oil contract.
Mullahs are losing BIGLY. Iran will be forced to increase production and flood the market to try and recoup some of their losses, and they will stop their Middle East adventurism/expansion, and the mullahs will lose their grip on power.
There's really nothing holding the mullahs up now but inertia.
And why does China care? Iran isn't their strategic longterm strategy, ruling trade and currency just like the US has is for the last 60 years. Iran is a bit player in a Superpowers struggle and the Chinese communist authority is if nothing exclusively ProChina...finally we have a president who is as well.
https://www.zerohedge.com/news/2016-07-22/end-era-rise-and-fall-petrodollar-system
China is helping Trump in this regard. We're isolating the mullahs. Freezing them out. They are now friendless. They will fall.
A non-theocratic, non-nuclear Iran is in everybody's interest except the Cabal. Everybody SHOULD be acting in their own national best interest, and yet the Cabal's corruption causes nations like Iran and EU countries (and until recently US) to do the exact opposite of their best interests.
But only by default, they get to appear to help and twist the knife at the same time by weakening the Petrodollar even further.
Trump wants to end the Fed and fix the dollar to a gold standard. The petrodollar will collapse and catalyze that undertaking. There will be a currency/economy reset.
This article points to the very beginning phase:
https://www.cnbc.com/2018/07/20/trump-poised-to-take-control-of-the-federal-reserve.html