Middle East abandoned by major power? So it is (4)
I believe the answer is:
thus
'so it is' is the definition.
(like so)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for thus that I've seen before include "an original Christmas gift" , "Like so" , "In this manner" , "It follows" , "In this way" .)