Germany has been a reliable ally of the United States for decades, but it looks like Donald Trump has seriously damaged that relationship. Americans still see the relationship between the two country as a very good one. Germany sees it very differently. After four years of Trump, they no longer trust the United States.
Can Biden cure this rift between the two countries? He will make it better almost immediately, but he probably won't be able to restore the pre-Trump relationship in only four years. It will remain in German minds that there is a possibility that the U.S. will return to Trumpism four years from now. That will make them very cautious in dealing with the United States.
The charts above are from a survey of Americans and Germans by the Pew Research Center. The Pew Research Center surveyed 1,007 Americans between September 22nd and 28th with a 3.7 point margin of error. Korber-Siftung surveyed 1,005 Germans between September 10th and 17th.