In possession of intelligence American leaked about men I'd compromised (4-6)

'in possession of intelligence' is the definition.
(able-minded can mean intelligent)

'american leaked about men i'd compromised' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'leaked' becomes 'bled' (bleed can mean to leak).
'about' means one lot of letters goes inside another.
'compromised' indicates an anagram (I've seen 'compromising' mean this (compromise can mean change)).
'men'+'id'='menid'
'menid' anagrammed gives 'minde'.
'bled' placed around 'minde' is 'bleminded'.
'a'+'bleminded'='ABLE-MINDED'