Soldiers back around Germany? That's amazing! (3,4)
I believe the answer is:
red army
'soldiers' is the definition.
(army of the USSR)
'back around germany? that's amazing' is the wordplay.
'back' becomes 'rear' (synonyms).
'around' is an insertion indicator.
'germany?' becomes 'd' (international vehicle registration code).
'that's amazing' becomes 'my' (both are expressions of surprise).
'rear' going around 'd' is 'redar'.
'redar'+'my'='RED ARMY'
(Other definitions for red army that I've seen before include "Revolutionary fighters" , "Left soldiers" , "Cold War divisions?" , "Leon's offensive baby" , "force" .)