I do not believe there is any I. tax Traety with Taiwan. Taiwan is not listed in IRS Pub. 901.
I recommend that you follow a strategy of deferring the taxes. Rollover the 401k to a self-directed IRA. For opening the IRA, choose an institution with internet access (most of the big name financial institutions such as Fidelity, C.Schwab etc. have that). This way you maintain maximum flexibility to direct your money to mutual funds, stocks, bonds etc. and engage in trading as and when opportunity develops.
In future years when you take money out, you would owe taxes to Uncle Sam. You would be required to file Form 1040NR. There is one withdrawal option called "substantially equal payment" which allows you to take money out of an IRA even before age 59 1/2 without paying the 10% penalty.
You may visit www.irs.gov and use their search for further information.
Good luck