I'm pretty sure I've seen Tacitus quotes to the effect that the Romans were actually quite terrified by the Germans and feared them as a major threat to the empire in Europe, but for the life of me I can't remember where this came from (Annals, Germania etc) and don't want to go on a wild goose chase for something I may have just come up with in my head.

I checked the FAQ, even going to the "what did the Romans think" section and couldn't find anything there on this.

Is it fair to say that the Romans feared the Germans and felt they were a true threat to the empire? What sources comment on the Germans as regards the threat they did/didn't pose to the empire and how Romans felt about them?

Thanks!