To take us on, perhaps, requires intelligence (4)
I believe the answer is:
nous
'intelligence' is the definition.
(I've seen this before)
'to take us on perhaps' is the wordplay.
'us on' can be anagrammed to 'NOUS'.
Though, I am not sure how the anagram is indicated.
'requires' is the link.
Can you help me to learn more?
(Other definitions for nous that I've seen before include "How the French describe their own" , "Informal common sense" , "Sound practical judgement" , "French common sense" , "Our (French); practical intelligence (colloq.)" .)