Writer has quotation on US top brass (8)
I believe the answer is:
pentagon
'top brass' is the definition.
(I've seen this before)
'writer has quotation on' is the wordplay.
'writer' becomes 'pen' (something which writes).
'has' means one lot of letters go next to another.
'quotation' becomes 'tag' (I've seen this before).
'pen'+'tag'+'on'='PENTAGON'
'us' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for pentagon that I've seen before include "government HQ abroad" , "Five-sided shape" , "top brass" , "Figure - US military HQ" , "military installation" .)