As I remarked at that time:

This is huge!
…
Reviving relations between Saudi Arabia and Iran will make a lot of new things possible.

That Iran and Saudi Arabia accepted China's mediation is a recognition of Beijing's new standing in world policies. That alone is enough reason for the White House to hate the deal.

I later summarized the diplomatic action in the Middle East:

For the last 30 years the U.S. considered the Middle East as its backyard. Twenty years ago it illegally invaded Iraq and caused 100,000nds of death and decades of chaos. Now China, by peaceful means, changed the balance in the Middle East within just one month.