Eastern leader, one stopping withdrawal of criticism (5)

'eastern leader' is the definition.

'one stopping withdrawal of criticism' is the wordplay.
'one' becomes 'i' (Roman numeral).
'stopping' means one lot of letters goes inside another (stopping can mean blocking a gap).
'withdrawal of' says the letters should be written backwards.
'criticism' becomes 'flak' (flak is a kind of criticism).
'flak' reversed gives 'kalf'.
'i' inserted inside 'kalf' is 'KALIF'.