The following is extremely simplified. You might also want to learn about 20th century treaties because I think those are critical to understanding the conflicts in east Asia.

Vietnam/Cambodia: proxy war between USSR and the US. Conflict originated from colonialism (see: French Indochina). Japan occupied the region towards the end of WW2 and when they surrendered the Việt Minh (communist) declared independence and opposed the return to French rule. France was like, hell naw and you get the First Indochina war. That ended with the country split into north and south (at the 17th parallel).The French, the USSR and China supported the split and convinced the North Vietnamese to accept. The US and the South Koreans did not agree. France left the conflict at this point and I guess that is why the Vietnam war was a new war 🤷‍♀️

Korea: Korea had been occupied by Japan since 1910. When the USSR and US defeated Japan they just kind of split the country in half, each responsible for administering a side until things settled down and they could have elections. As far as I understand there was no intent to colonize the old fashioned way, but this was also a proxy war so…

Desert storm: the popular answer is going to be oil but I think it’s important to understand the impact the cold war had on this part of Asia too. I am way less familiar with these wars but the wiki article on the Cold War in Asia looks pretty promising.

Al-Shifa pharmaceutical factory: This was bombed because of suspected ties to al-Qaeda. The US was in conflict with al-Qaeda at the time in retaliation for the embassy bombings. Again, this is all linked back to the Soviet-Afghan war.

Afghanistan the first time (?): do you mean 2001? The US decided the al-Qaeda was behind the attacks and that the Taliban was helping them. The Taliban was the government of Afghanistan. The US attacked them because they did not hand over bin Laden.

Iraq the second time: Oil. The Gulf war was never resolved. Regime change was the stated policy of the US since 1998. Bombing happened right after that (with the UK helping), but 9/11 gave them to excuse they needed to actually invade.

Iran: we’ve come full circle to the proxy wars again. Maybe that’s a stretch but there is a shift in who the “world powers” are and I think that’s raising the stakes in a conflict that is otherwise probably mostly about oil. Way back in the 1950s the Iranian government nationalized the oil industry so the US/UK supported a coup d’état which gave the shah (hereditary ruler) more power. The Iranian revolution replaced the shah with the Islamic Republic. Iran and the US have been in indirect conflict in the region since then basically. There are pro and anti Western groups in the middle east and it comes down to access to oil. Why now? Israel asked. Iran and Israel are enemies and the US has interest in regime change.