When Apple Inc. was ordered by European regulators to pay $14.5 billion plus interest in back taxes to Ireland, the giant technology company seemed to be facing an expensive headache.

Turns out it's a headache for the U.S. Treasury Department as well.

Under current U.S. tax rules, specialists say Apple would probably be able to claim a foreign tax credit for the repayment, allowing it to lower its tax bill in America, where the 35% corporate income-tax rate is one of the world's highest. Unlike other industrialized countries, the U.S. taxes its multinational corporations on their global income — while allowing a dollar-for-dollar credit for the foreign taxes they've paid.