In some respects, I feel like this Iran situation has a lot to do with the Straits of Hormuz.
The Straits are, currently, apparently a no-go zone for shipping, and with the globalization of trade and the amount of European reliance on Chinese and Taiwanese manufacturing this amounts to an economic hit attack on trade between Europe and Asia especially when overland shipping from the East Asia has to go through West Asia, and a number of countries that can't be trusted with a number of important products passing through.
This concentrates shipping to Europe through Panama, around the horn, and around South America. This puts that shipping at the mercy of potential US blockade, essentially cutting off any Chinese, Japanese, Indian or Taiwanese logistics support of Europe in case of conflict with the US or Russia.
Starting shit with Iran just FUCKED a number of markets, from Oil to Tech, and markets will reflect that in the morning, with those who have stock on hand being king, and those who have stuff on the wrong side of a closed shipping lane suffering.