US ordered TSMC, not Taiwan the country. The vast majority of sales are made to US based firms so they likely have a lot of sway.

US is the major customer of TSMC, so they can order them, not to mention we protect them with defense pacts, so they might want to actually listen. Pretty sure they make some of our military grade chips as well.

Cutting edge chips are used in cutting edge military hardware. TSMC provides a lot of the chips used in advanced American weapons. Turns out a faster chip in a missile makes the missile better able to make sophisticated split second decisions.

US can order most of its allies to do anything. Remember when the US thought Edward Snowden was on the Bolivian presidential airplane and within the span of like, half a hour, managed to get all of western europe to deny airspace to Bolivia, ground the literal presidential plane and search him like a dirty drug mule? Was pretty awkward after that when Snowden wasn't even there.

[Cobbled from Reddit thread]