You're missing the implications. How much foreign business did Apple do in the 1980s? Look here:
http://graphics8.nytimes.com/packages/pdf/business/MemoOnOff...
>The Apple case study examines how Apple Inc., a U.S. corporation, has used a variety of offshore structures, arrangements, and transactions to shift billions of dollars in profits away from the United States and into Ireland, where Apple has negotiated a special corporate tax rate of less than 2%. One of Apple’s more unusual tactics has been to establish and direct substantial funds to offshore entities that are not declared tax residents of any jurisdiction. In 1980, Apple created Apple Operations International, which acts as its primary offshore holding company but has not declared tax residency in any jurisdiction. Despite reporting net income of $30 billion over the four-year period 2009 to 2012, Apple Operations International paid no corporate income taxes to any national government during that period. Similarly, Apple Sales International, a second Irish affiliate, is the repository for Apple’s offshore intellectual property rights and the recipient of substantial income related to Apple worldwide sales, yet claims to be a tax resident nowhere and may be causing that income to go untaxed.
That's not some guy in his pajamas, there. It's a Senate report. For most US companies the whole point of the lowered Irish tax rate is to pay that on profits you've moved offshore.
And while most of Apple's profit would probably still come from other markets if it weren't playing these kinds of offset pricing games, Apple has moved billions of dollars in profits out of the US to avoid taxes.
It's not just Apple, either. This is why the effective US tax rate for corporations is 12.6% even as the statutory rate is 35%. I suspect that figure would be a lot lower, too, if only multinationals were considered.
This is the elephant in the tax tent: The IRS has wide latitude when determining what's reasonable for companies to charge subsidiaries for goods and services (and vice versa). But it's easy to arbitrarily complicate these kinds of arrangements.
And it's pretty subjective to start with - how much should Apple pay Apple Sales International to use a patent that nobody else is licensing? How would you even determine the fair market value? There are rules, of course, but even assuming there's no undue influence by corporations (and you can't assume that), imagine writing a set of rules that covers every conceivable business arrangement between multinationals that doesn't leave any grey area. Can't be done.