surrendered contries units

so i understand surrenered countries units hold for their orders...
but what happens if i attack (with support) and bump the guy. does it die, or randomly choose an open available country to retreat into?
(as in i have a ship in norway, denmark and belgium and attack a guy in the north sea with belgium with support from denmark and also move norway to norwegian sea. where will the guy in north sea retreat to if the country is surrendered? will he retreat into now vacant norway or holland (also vacant) or london (vacant)
thanks
but what happens if i attack (with support) and bump the guy. does it die, or randomly choose an open available country to retreat into?
(as in i have a ship in norway, denmark and belgium and attack a guy in the north sea with belgium with support from denmark and also move norway to norwegian sea. where will the guy in north sea retreat to if the country is surrendered? will he retreat into now vacant norway or holland (also vacant) or london (vacant)
thanks