> South Korean companies have been mostly relying on short-term visas or a visa waiver program called the Electronic System for Travel Authorization, or ESTA, to send workers needed to launch manufacturing sites and handle other setup tasks, a practice that had been largely tolerated for years.
It sounds to me like they had relied on a grey area. The most obvious conclusion is that pressure from the top down in ICE caused their agents to "hunt around" and look for "big arrests." When political pressure from South Korea mounted they had to reverse themselves.
Short-term visas might be entirely appropriate for someone who's going to be working in the country for a short time to set something up. I've worked under one myself (You usually need to justify why someone already in the country couldn't do it, but "I designed the thing and literally no-one in your country has seen one before" tends to work). visa-waiver programs like the ESTA generally are not: they're mainly for tourism, conferences, and business/sales meetings, and the latter can get a little blurry depending on how much you are demoing something, but if you're doing actual work and you're being paid directly or indirectly by a US company you're probably not covered (which surprises a lot of people, and there's often stories of people getting kicked out of the country for relatively small pieces of 'work').
Either way, if these were actually workers in the country temporarily and in good faith to set up manufacturing, then it would neither seem to be a particularly good crackdown on illegal immigration nor encouraging manufacturing to be set up in the US.
It's the USA (collectively) that's in the wrong here. You can't both beg a Korean company to build and start up a battery factory in your country and not provide any mechanism for the people needed to make that happen to be present in your country.
> South Korean companies have been mostly relying on short-term visas or a visa waiver program called the Electronic System for Travel Authorization, or ESTA, to send workers needed to launch manufacturing sites and handle other setup tasks, a practice that had been largely tolerated for years.
It sounds to me like they had relied on a grey area. The most obvious conclusion is that pressure from the top down in ICE caused their agents to "hunt around" and look for "big arrests." When political pressure from South Korea mounted they had to reverse themselves.