As long as the French continued to occupy the Rhineland, it functioned as a form of "collateral" under which the French could respond to any German attempt at overt rearmament by annexing the Rhineland. Once the last French soldiers left the Rhineland in June 1930, it could no longer play its "collateral" role, which opened the door for German rearmament. The French decision to build the Maginot Line in 1929 was a tacit French admission that it would be only a matter of time before German rearmament on a massive scale would begin sometime in the 1930s and that the Rhineland was going to be remilitarized sooner or later.Emmerson, p. 25.Young (1996), pp. 19–21. Intelligence from the Deuxième Bureau indicated that Germany had been violating Versailles throughout the 1920s with the considerable help of the Soviet Union. With the French troops out of the Rhineland, Germany could be expected to violate Versailles only more openly.Young (1996), p. 21. The Maginot Line, in turn, lessened the importance of the Rhineland's demilitarized status from the view of French security.
