[Tomte]

"A military base" is really understating it.

Germany not only has several important bases, like Ramstein with the largest American military hospital outside American soil, and several other large bases (K-Town), but also houses two of eleven unified combatant commands in a single city: EUCOM and AFRICOM are both in Stuttgart.

[RamblingCTO]

Needless to say there's plenty of CIA around as well. Just look at the welcome guide for Frankfurt for new officers in the field from one of the more recent leaks. Can't remember which.