In a provocative move, the US announced deployment of 3,000 additional troops in West Asia on Monday, claiming alleged Iranian threat to ships in the region
I don't quite understand what's going on here, what's the context? I read that Iran has been seizing oil ships, which is pretty based, but what is the bigger picture? Would appreciate if anyone could throw some light on it.
Iran and the United States have essentially been in an oil tanker war for a while now. The United States seizes oil tankers heading to China and elsewhere because they have put Iran under sanctions which don't permit them to transport oil anywhere. Iran seizes oil tankers too. Such conflicts over oil tankers are not new - they were a part of the Iran-Iraq war a few decades ago. Of course, the United States of all fucking countries complaining about Iran stealing oil is unbelievable, considering they routinely steal Syria's oil and have just seized Venezuela's CITGO. There's not really a lot of nuance here - the United States is obviously in the wrong.
Geopolitically, this area remains important to the United States despite all the Ls they've been taking recently because of the presence of the Suez Canal, the Gulf of Aden (the strait at the other end of the Red Sea, which Yemen sits on), and the Gulf of Oman, which is the strait that connects Iran, Kuwait, Qatar, the UAE, and Bahrain (as well as some ports in Saudi Arabia) to the wider ocean. Russia, China, and the United States have been battling for control of these straits because they are so pivotal to global shipping. Until the Arctic passage above Russia opens up[^1], Russia must go through the Suez Canal in one way or another to get their oil around the world. Well, that's not technically true, but they definitely have to go through either Denmark (starting from St. Petersburg) or through Istanbul and the Strait of Gibraltar (via Black Sea ports), and all of these are NATO members.
To this end, America has caused or in some ways helped along conflicts in Yemen and Somalia with troops in the latter, and obviously they have a long-standing military relationship with Saudi Arabia, which border the Gulf of Aden. China's only foreign naval base is in Djibouti, which sits on the Red Sea - this isn't a coincidence. Russia has been making friends with Egypt, Saudi Arabia, and I think Eritrea - again, all on the Red Sea.
There's a similar situation going on over at the Strait of Malacca in the Indo-Pacific, which doubly explains why the US is so focussed on getting Malaysia and Thailand under their thumb. Whoever controls the straits of the world controls global shipping and could hypothetically strangle China and other upstart nations.[^2] This is why the Belt and Road Initiative, going over land as much as possible, is so critical.
[^1]: Russia has been investing increasingly in icebreaker ships for exactly this purpose - and wouldn't you know it, newly joined/soon to join NATO members Sweden and Finland are awfully useful for getting a little leverage over that passage!
[^2]: China has shown interest in building a canal through Thailand (it's quite a thin country if you are unfamiliar) but this has always been one of those "It would be cool if we could, but alas we're not interested at this time due to X and Y factor, the costs, etc" things. I think Thailand is also concerned that it might weaken their hold on their southern provinces.