Re: They can't leave the money overseas forever.
Leaving aside the rights/wrongs and the Apple specifics, but can they leave it overseas for ever?
Firstly they can use the offshore money to build factories, buy raw materials, buy competitors - but this is pointless since they wouldn't pay tax on those anyway.
But they could use them to buy other companies/investments and become essentially a hedge fund.
There would be no US tax to pay if Apple Bermuda bought shares on the US stock market, or bought Heathrow, or the port of Grimsby in the same way that the Dubai National Investment corp, or the Govt of Singapore did. then Apple's share price would rise, since it owned $Tn of profitable investments, and the shareholders would be happy.
Ultimately it could stop bothering to make shiny things at all.