here's an easy one: tax their US profits on a sliding scale in proportion to their relative levels of employment in the US. So if Intel makes 60% of their profits in the US, and their workforce is 60% US, they pay no incremental. But if HP makes 95% of their profit in the US, and 30% of their workforce is offshore, they get hit with a surcharge I like the concept of incentives for employing our own, and your scenario could be a good start. But such a policy would require an extraordinary reform of the tax code (which is also a good thing). Right now, a corporate tax attorney can convince the IRS that up is down, and that black they see is really red. Maybe gross revenues is a better (at least easier to define) benchmark.
What then is the motivation for keeping a US presence? Economically, would it be better to move offshore and pay import/export taxes?