I don't have specific figures.
I am saying, without having to look hard I can reasonably assume they hold a large number of employees outside the USA based on the fact the hold so many offices outside the USA, which they don't keep secret.
I wouldn't consider the fact they don't publish their employee totals in each country an attempt at "Hush Hush" but they claim to have.... on a worldwide basis, 19,835 full-time employees as of December 31, 2009.
How many of them are in the USA? I would guess at least 2000-4000 employees to run the Googleplex.. if you can find how many USA employees they have it is a simple subtraction away from how many outside the USA.
It doesn't seem very hushed tho.