TSMC looks to double down on U.S. chip factories as talks in Europe falter

I have no knowledge of the situation, why did they choose Arizona?

Chandler Arizona is the site of Intel's 14nm Fab[1]. There is a large pool of local talent that they can tap into. Add to this the fact that Arizona has relatively favorable laws for corporate investments and a relatively low cost of living and it's a natural choice.

[1]: https://en.wikipedia.org/wiki/List_of_Intel_manufacturing_si...

It's also geologically fairly stable.

Is this really a primary concern? Most of their main fabs are in Taiwan, which is very seismically active.

That's precisely why. It costs A LOT to make a fab seismic resistant

They've done this and know the costs

My point is that if you already successfully operate several seismically stable fabs and you're building a new one that's gonna cost you tens of billions of dollars anyway, there must be other factors that are higher on your requirements list.