Foreign Office with its back to the wall (6)

I believe the answer is:

bureau

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'foreign office' is the definition.
('office' in French)

I don't understand how the remainder of the clue works.

(Other definitions for bureau that I've seen before include "Chest of drawers or office" , "Room" , "French office - desk" , "Item of furniture" , "Office; writing desk" .)

I've seen this clue in The Globe and Mail.

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