Scene of military operations? (4,8)

I believe the answer is:

army hospital

I'm a little stuck... Click here to teach me more about this clue!

'scene' is the definition.
The answer and definition are not the same part of speech.

'military operations?' is the wordplay.
'military' becomes 'army' (the armed forces).
'operations?' becomes 'hospital' (I can't explain this - if you can you should give a lot more credence to this answer).
'army'+'hospital'='ARMY HOSPITAL'

'of' acts as a link.

Can you help me to learn more?

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

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