> sanctions have successfully applied to countries such as Russia, Iran, etc for decades.

Largely because other countries are willing to go along with it, and to the extent they are willing to do so.

Even NATO countries import Russian gas. The UK rolled back sanctions on Russia to import diesel earlier this year. Most of the rest of the world did not impose effective sanctions and lots of people trade with them (including huge economies like China).

The rest of the world is to dependent on China to want to get involved. The US might succeed in the current administrations attempt to split the world into new cold war spheres of influence (because people are scared of China too) but its not going to be easy, it will be painful, and its not going to get many countries to completely agree to what the US wants.