Well that's a pretty selective view of history. A few Tibetans may debate your benign view of China's imperialist policy (though getting rid of a medieval theocracy can't be all bad), as may the various countries debating ownership of islands in the South China Sea, which are nowhere near South China. As for the significant Muslim populations of west China, obviously self determination is a privilege they don't need according to the Han Chinese. The many African nations 'benefitting' from Chinese infrastructure support may also think again when they realise they have lost control of their own natural resources. I'd say that China is the most aggressively imperialist nation around today, they are just clever about the way they do it.
Admittedly Iran, as Persia, got its imperial phase over and done with some time ago, only to pioneer 'back to the future' state building by adopting .........a medieval theocracy. You can post as many links to anti Israeli articles (and I am no supporter of Israel) as you like, but given the regular threats of genocide and total destruction coming from Iran, it may not be surprising that they have a plan to stop this happening. Although Iran's capability to deliver to its threats must be pretty questionable. Poor Iranians, their own regime is dragging them back to the Stone Age, no one else needs to do much except let it rot.
The usual over generalised anti -Americanism seems to dominate here, sure they are far from perfect, are definitely self interested and have on occasion abused their status as world's most powerful nation. As of course the British (of if you prefer English) did when we were top dog. But you'll be begging to have them back when the Chinese take over. And any one who truly believes that the North Korean people would not benefit from removal of the Kim dynasty, which routinely deliberately allows large sections of its own population to starve, really has no respect for human life or dignity.