Not intervening — a variety of sizes satisfactory in Dior article (7-5)
I believe the answer is:
laissez-faire
'not intervening' is the definition.
(as in laissez-faire economics)
'a variety of sizes satisfactory in dior article' is the wordplay.
'variety of' is an anagram indicator.
'satisfactory' becomes 'fair' (similar in meaning).
'in' means one lot of letters goes inside another.
'dior article' becomes 'le' (French definite article - Dior is a French company).
'sizes' with letters rearranged gives 'issez'.
'a'+'issez'+'fair'='aissezfair'
'aissezfair' going inside 'le' is 'LAISSEZ-FAIRE'.
(Other definitions for laissez-faire that I've seen before include "not getting involved" , "Policy of non-interference" , "Practice of non-interference" , "Doctrine that governments should not interfere in commercial matters" .)