Russia would still be in Afghanistan if we hadn't co-opted the Mujahideen in its entirety. We spent $30b so that Russia would lose. Iran-Contra? $11 million, of which like $1m actually went to the Contras.
We also occupy the Middle East through relations with Saudi Arabia, the UAE and Israel. Saudi Arabia is bogged down in Yemen, Qatar has resisted their embargo and we're stirring shit up by moving our embassy to Jerusalem which limits our goodwill elsewhere. Meanwhile Iran and Russia are aligning, Turkey and Russia are aligning and Syria and Russia are already aligned.
Meanwhile, we've pissed Pakistan off like they don't matter, India is doing their own thing and much of what's left is former Soviet near-abroad. They don't need to take it over; if they can exert influence their frontier is secure. Meanwhile Turkey and Iran are great markets to be in.
As for China, Southeast Asia has been dealing with Chinese empires for like four thousand years. Robert Kaplan has a passage in Asia's Cauldron where he talks about how surprising it was that the Vietnamese were friendly to him. His Vietnamese host points out that the US only fought a war with Vietnam once; China has traded fire with them three times since and dozens of times previously and is far and away Vietnam's largest trading partner.
Western perspectives on China are heavily shaped by WWII and its outcomes, probably the worst crisis in Chinese history since the Mongols. They're not a bit player on a historic scale.