My father went to med school in Poland. When he moved to Israel, he had to retake one year and redo his residence.(He was then drafted and served as a naval surgeon.) When he emmigrated to America, he had to redo his residence here.
To allow otherwise would allow to many doctors in markets to keep evil competition from showing its face...this way, numbers kept small with obstacles....no compeitition...better revenue. Of course you get screwed...but you have insurance for that.