In a report from Reuters, TSMC chairman Morris Chang said that the company would only decide on whether or not they should open up a chip plant in the US come 2018. Note that this does not mean that TSMC will open up operations in the US, it’s just that their discussions and decision will only be made in 2018. For all we know the company could decide they’d rather not.
In a statement provided by TSMC spokesperson Michael Kramer, “We won’t make a decision until next year. We would sacrifice some benefits if we move to the States. But we have flexibility in Taiwan. If an earthquake happened for instance (in Taiwan), we could send thousands of people here as support, whereas it’s harder in the States.”
According to Reuters, it is estimated that TSMC gets about 65% of its total revenue from the US, which means that a lot of companies in the US do rely on their services.