at least for S Korea, their citizens can enter the US on tourist visas for a significant period of time, as long as they go back home every few months (Which they want to do anyways to see family.) and then can come back again.

 
How it works for other nations, especially China, must be another story.

thisisalloneword1234,
  I would agree with you. The Asians & Other non-United States residence make it just by living where they are and traveling to the US for work as they do for any other job.

thisisalloneword1234,  
  Well aren't you a genius. Dah !!!!