Bombs northern country explodes externally (5)

I believe the answer is:

nukes

'bombs' is the definition.
(I know this)

'northern country explodes externally' is the wordplay.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'country' becomes 'UK' (United Kingdom).
'externally' means to remove the middle letters (only the external letters are used).
'explodes' with its middle taken out is 'es'.
'n'+'uk'+'es'='NUKES'

(Another definition for nukes that I've seen is " Destructive weapons".)

I've seen this clue in The Independent.

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