In an ideal world, supply would rise because landlords would want to make more money in total.
So the question is why isn't supply rising? Is it because existing landlords aren't funding housing construction or the difficulty of entering the market?
Surely it cannot be that the supply of land is that limited. Or is it? Due to zoning regulations?
It doesn't always work smoothly, sometimes players can corner the market, or become too big and own both side of development, and rental. That is why we need an agency to look at price fixing, monopoly and stuff like that.
In a good system, government doesn't subsidize cost. It just enters whenever the system is broken to work based on supply and demand of market.
The world isn't divided into the countries that are under American hegemony and the countries that are under Chinese hegemony. It's more that there are the countries under American hegemony, the countries on mostly-friendly terms with the Americans but able to say no to them, and the small number of countries that are entirely cut off by the USA.
This last group tends to not want to just trade one hegemon for another, they try their best to become self-sufficient and able to say no to everyone. Iran is very much in that category: just because they're on friendlier terms with China than with the USA doesn't make them beholden to them.