Also, he withdrew from the Universal Postal Union (Treaty of Bern 1874) which the Chinese Communists were using to great effect to smash us over the head.
Have you ever noticed the weirdness with shipping things to and from China?
I did, and it started to piss me off. (NOTE: I wrote this back during the Trump Presidency a few years back)
I went to a website at random called ONLINE SHIPPING CALCULATOR to compare the cost of shipping a 1 lb. package from Washington DC to Beijing, and then compared to shipping the same 1 lb package in the reverse, from Beijing to Washington DC:

What is behind this BS is called the Universal Postal Union.
I knew nothing about this, then stumbled across it by accident some years ago. It has the word "union" in it, which is repulsive enough in most industrial contexts, but otherwise sounds innocuous.
It is NOT innocuous, and the Communists in China have been milking this for all it is worth and more.
The Universal Postal Service was brought into being by The Treaty of Bern in 1874 with the ostensible and laudable goal of making sure that mail could be sent between countries around the world without worrying about mail being returned to to insufficient postage because the cost of delivering mail in the receiving country might be far above that in the sending country.
From the Wikipedia entry on the Universal Postal Union:
The treaty provided that:
One important result of the Treaty was that it was no longer necessary to affix postage stamps of countries that a mailpiece passed through in transit. The UPU provides that stamps from member nations are accepted along the entire international route.
This all sounds absolutely great. Then, in 1948, the Universal Postal Union became a "specialized agency" of the United Nations when it was founded. And like every damned thing the UN has touched, the International Grifters known as the UN, Leftists all, decided in 1969 to implement "Terminal Dues" which took into account the tonnage/volume shipping between countries and...to "equalize" things and "help" developing nations, they instituted a standard progressive system of Terminal Dues, and assigned countries a value that indicated their degree of advancement.
United States would be a Tier I country, and back then, a country like Communist China would be a Tier III.
This meant that in addition to a simple disparity in volume of mail shipped to determine the "Terminal Dues" paid, there was also a Marxist element that required Tier I countries to pay MORE per volume/tonnage disparity. Before 1969, it was a straight up "Terminal Due" based on simple measurement of disparity in volume or tonnage.
After 1969, If you were a Tier III like Communist China, you paid X $ "Terminal Dues" for each unit of measurement. However, if you were a Tier I like the United States, you paid X $ times whatever the tier multiplied your "Terminal Dues" by, just to "equalize" things between wealthier and less wealthy nations.
I had to poke around to find this, but this document defines the tier system that determines who is the taxpayer (such as the USA) and who is the grifter who takes advantages of the subsidies provided to them by the Universal Postal Union: LINK TO UPU DOCUMENT: Classification of countries and territories for terminal dues and Quality of Service Fund (QSF) purposes for the 2018–2021 period
How Marxist of them.
And lest the lesson be lost in this current push to implement a international corporate tax to be paid to the UN, you can look to history to see just how these International Grifters handle these types of things with no elected representation: In 1974 they tripled this "Terminal Dues", and in 1979, tripled it again. Then in 1984, increased it again by 40%. This is how THEY do taxes.
When President Trump took office, surely someone who understands business better than 99.999% of the people governing us, and better than 100% of the people who populate the UN, he was likely fully aware that we as taxpayers pay a subsidy to China (via the Universal Postal Union at the UN) to give them a significant and unfair competitive advantage, and announced he was going to withdraw the US from the Universal Postal Union. That completely threw them into an uproar "How dare he protect the interests of his own citizens!" This article from the Heritage Foundation describes it a bit: The Heritage Foundation: A U.S. Victory at the Universal Postal Union
Granted, it wasn't a complete victory to me. That would have been an elevation of China to Tier I, a simple withdrawal. The Communists still get their ill-gotten subsidy from the UPU, and we pay a little less, but we still pay.
Personally, I look to President Trump's approach to this subject of UPU Terminal Dues in the "Trade War" as evidence he was really in this fight for his country, and why so many of us admire him so much and are outraged by this fraudulent election.