Coincidentally, the OP hasn't been back to debate this point.
For the record, I see nothing wrong with how Apple has structured their businesses, and the tax liabilities from that.
People make similar decisions, though on a much smaller scale, every year and everyday. I wonder how many people criticizing Apple in this thread have ever chosen to buy something online - because of sales tax. Or used a friend's EDU discount. Or paid for a service or goods under the counter in cash to get a better price.
Or - chose to live in a low sales tax state. Or chose to live in a low income tax state. Or taken advantage of a back to school tax holiday.
Or.... decided that you could go back to school because of the tax breaks, (where if there were no tax breaks you couldn't afford to). Or for that matter bought anything that had a tax incentive attached, something you could or would not have purchased otherwise.
That's all Apple did. It made decisions about its business structure that - legally - minimized its taxes.
===
It also
much more complicated than most people here are giving credit for as this isn't just Apple and the US government involved.
There is no question that Apple is paying income tax internationally. As already stated there are treaties to ensure that company only pays tax on it's income once. Apple gets a 'dollar for dollar' (Cook's words) credit for that tax paid. If the US changes its tax laws to extract more taxes from Apple, it will be
instead of that tax going to a foreign jurisdiction.... Apple will get the credit for the tax paid to the US, and apply to its international liabilities. On the surface, Americans might think this is a peachy-keen idea, and really does no harm since Apple essentially pays the same tax on balance, globally.
Pisses off American trading partners though, and you need trading partners if what you want to do is, you know... trade, eh? Piss off the trading partners enough (by scooping their taxes, for instance) and they may decide to close their doors to American goods, putting even more Americans out of work. Consider that despite the current self-denial, the US is still one of the biggest goods exporters in the world - perhaps still #1, it's been a couple of years since I looked. America needs to export to maintain its economy. Stealing other nation's income tax lunch money isn't usually considered a good way to build the warm and strong trading ties you need to export goods.