It's subject to U.S. taxation only if Google ever decides to bring it back into the U.S. via a dividend. Alternatively, they can use that cash to fund foreign

It's subject to U.S. taxation only if Google ever decides to bring it back into the U.S. via a dividend. Alternatively, they can use that cash to fund foreign growth without ever facing US taxation. Postponing taxes for about 7 years is roughly the same as avoiding those taxes altogether, based on a comparison of the time value of money calculations (because future amounts of the same value are worth relatively less).