Bet Russia surprisingly losing international is hard to understand (8)
I believe the answer is:
abstruse
'is hard to understand' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for abstruse that I've seen before include "Difficult to penetrate or understand" , "Obscure or recondite" , "Hard to understand, complicated" , "Busts are oddly difficult to understand" , "Incomprehensible to those with normal understanding" .)