And they are doing horrible right now and present a threat to our allies if they make nukesNot really, sane people in government want containment over war, as the last few times war was used, it didn't go so well, especially with the public. Containment is not only more viable but also a lot easier to sell with the public.
Iran's government would be suicidally stupid to cause a war.
War with China is a lot more likely. China is growing desperate and have been on the brink of war with Taiwan and it gets worse.War with China over Taiwan won't happen. China won't attack the US or its direct allies (ie, Japan, South Korea, and Taiwan). Invading Taiwan would be suicide, as the Taiwanese are heavily entrenched and prepared to bleed the Chinese dry. Taiwan is like the US during the early 1800s; sure they'll lose in an invasion, but the invasion would be so costly it would never happen.
Taiwan is important to trade (protecting trade routes), and keeping it out of Chinese hands is important to keeping China contained, so the US will help out. Any massing of troops along the east coast across from Taiwan would be noticed by satellites long before Chinese soldiers set foot on Taiwan, so the US would be prepared early. China would be in a losing position as their fleets could be taken out by nukes, meaning China only nukes would be in their submarines that were still at sea... and they can't really do anything substantial on their own they would affect the war effort besides just further antagonizing everyone. So they won't try in the first place.
The CCP is evil, but they're not stupid. If they were stupid, they wouldn't have outlasted the Soviet Union and managed to survive for almost 70 years.
If China does decide to try aggressively expanding, it will be towards the Middle East and India. The US probably wouldn't get involved. But I think that the Chinese already have their hands full trying to manage what's already on their plate.
As for war with Iran, it's possible, but I doubt the US will get involved unless Iran actually gets nukes. Unlike the CCP, the Iranians might have religious motivations to go to war and might be committed to following through with their beliefs, which makes them dangerous. I'm not confident that they would be like South Korea where they have nukes but are sane enough to never actually try to use them. I think that the moment it was discovered that Iran had nukes, Israel or Russia might get involved and take hostile action towards them, and I don't think the US would let that slide (Iran getting nukes) either.
This is one of those cases where I know what is going in but j can't say anything to help my case.
I did just read a whole bunch on it at work, and you are right in some regards but wrong in others.
Also surprisingly enough. The US Ic I work with seem to think we won't go to war over Taiwan.