Australia's troubles with China are especially interesting because they seem to be made worse by the US.

Australia can't get much satisfaction by taking a case to the WTO, because the US sorta broke it for the time being. Ooops.

China also needs less Australia grain, in part because the US started a tariff war to get China to agree to buy US products.

The thing is that most exporters (EU, Canada, US, Aus) have generally similar complaints about China. So if they were addressed together, they would actually have some leverage.

But instead, it's piecemeal approach. So China stops buying from Canada because of the Huawei trial, and buys from Australia. But then stops buying Aus, and buys French, etc....

And there's massive asymmetries. China's a huge market, so imports of xyz product from Australia might represent 10% of China's imports of that product, but 60% of Australia's exports. It's always higher stakes for the exporters.

Importers have a lot more discretion and ability to restrict imports under WTO rules, so there's plenty of legal options China can use to restrict or limit imports.

And China faces essentially little repercussion for these moves. Exporters blocked today will come back tomorrow

US distillers grain exports have been on and off for the past decade due to phyto checks, GMO issues, anti-dumping probes, etc... But if China let them back in tomorrow every US firm would be rushing to export to China again.