The Nazis had some intention of annexing a large swath of northeastern France, replacing that region's inhabitants with German settlers, and initially forbade French refugees from returning to the region, but the restrictions were never thoroughly enforced and were basically abandoned following the invasion of the Soviet Union, which had the effect of turning German territorial ambitions almost exclusively to the East. German troops guarding the boundary line of the northeastern were withdrawn on the night of 17–18 December 1941, but the line remained in place on paper for the remainder of the occupation.