My entire life USA/IRAN IRAN/USA has been more hot than anything Russia/USA or China/USA. China/Russia like you say are peer competition, that can be worked out. I love the Chinese, I love China, wish I could visit there again. Pre-Ukraine I held Russian in esteem and wanted to visit St Petersburg. And those countries welcomed me and never called for me/my families death during my lifetime. Iran almost my entire life has vocally stated they want me and America dead. Their political leaders. Their spiritual/religious leaders. Their people massed in chants. All want me dead and my society destroyed. I mean they parade ballistic missiles and have banners calling for out deaths while shouting out calls for our deaths. Tehran is filled with murals against us. That combined with continuous low level hot conflict, I don't see the three in anywhere near the same light.
China wants to win and prosper. Russia wants to win and prosper. Iran wants what a strict, severe Islamic theocracy wants, and wants revenge against me/my people/my country for past grievances. They just admitted to murdering 3000 of their own people (and since they only admit to 10% of political executions it could be much much more) in could blood on the streets. I believe them when they say they want 'death to America'.
China wants to win and prosper. Russia wants to win and prosper. Iran wants what a strict, severe Islamic theocracy wants, and wants revenge against me/my people/my country for past grievances. They just admitted to murdering 3000 of their own people (and since they only admit to 10% of political executions it could be much much more) in could blood on the streets. I believe them when they say they want 'death to America'.