Fixing sentences with object and complement after a verb
Different from other verb complements that you can place directly after the verb and before the object, the verb complement 来 and 去 require the object to be placed between the verb and them, 


Insert the object between the verb 回 and the verb complement 来 as in '(回)中国(来)' = '(back to) China (here)' connects the object with the verb in Chinese grammar
Place the object after both the verb 回 and verb complement 来 as in'(回来)中国' = '(back to here) China' , the verb and the object would become disjointed. 


The verb complement that can be placed directly after the verb and before the object here is 到, as in '回(到)中国' = 'back (at) China' not '回(来)中国' = 'back to (here) China'