Chaotic situation is cool in America, on reflection (5)
I believe the answer is:
snafu
'chaotic situation' is the definition.
(I've seen this in another clue)
'cool in america on reflection' is the wordplay.
'cool' becomes 'fan' (fan can mean to cool down).
'in' means one lot of letters goes inside another.
'america' becomes 'US' (United States).
'on reflection' says the letters should be written in reverse.
'fan' placed into 'us' is 'ufans'.
'ufans' backwards is 'SNAFU'.
'is' is the link.
(Other definitions for snafu that I've seen before include "mess as usual" , "Chaotic state, mess" , "Slangy acronym meaning in total confusion" , "Mess table" , "confused activity" .)