Unreliable Foreign Office abandons foundation in trouble (2-3-3)

'unreliable' is the definition.
(in-and-out can mean unreliable)

'foreign office abandons foundation in trouble' is the wordplay.
'foreign office' becomes 'FO' (abbreviation).
'abandons' indicates named letters should be taken away.
'in trouble' indicates anagramming the letters.
'foundation' with 'fo' taken away is 'undation'.
'undation' is an anagram of 'IN-AND-OUT'.