Actually, most of the large CROs are moving away from allowing any monitor to cross the border. They realize that it not only costs more to ask their monitors to travel internationally, but it takes a whole lot more from their monitors and their personal life. They've decided it's a much better business decision to hire an experience CRA who lives in Mexico to monitor all the Mexican sites and a CRA that lives in Germany to monitor all the German sites and keep the US CRAs inside the USA. It's just not cost-efficient to send a monitor from the USA to Mexico one week and Germany the next week.
Your bilingual skills will make you especially marketable in the South and Western USA- the large CROs will like that a lot... but in these tough times, I doubt you'll get any opportunities to monitor in Europe as a US-based CRA.