The most common and most likely answer to this crossword clue is the 9 letter word DEPRESSOR
D
E
P
R
E
S
S
O
R
Buddy explains!

The straight part
We know that "German situation, which/could bring one down" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case german situation, which/could bring one down = depressor.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DEPRESSOR mean?
DEPRESSOR noun- Anything that depresses
- An instrument used to push something out of the way during an examination
- Any of several muscles that pull down
- Anything that lowers blood pressure