Never Pay U.S. Taxes Again - Legally

How does the IRS intend to collect money from someone who is no longer an American citizen, regardless of any supposed American tax liability and/or net worth and/or time spent in America? Would America provoke an international incident over a few hundred thousand dollars of taxes supposedly owed?

I doubt it. They’d probably just give the person concerned (or any businesses they are involved with) a good shafting if they ever ended up in under US jurisdiction somehow. That can often be enough of a motivator, if you are an internationally mobile person.
This sort of taxation nuttiness isn’t just confined to individuals. Barclays Bank is one of the largest UK banks, and a few years ago got clobbered by California demanding that it pay taxes on its total international income in sixty countries, not just locally. Brief summary

I hear they get sent to FPMITAP.

Yep. That’s it.
Feds & IRS lock you up, no job, no income, and NO TAXES! :rolleves:

Did you read anything in this thread but the OP?