"An ineffective line of defense that is relied upon with undue confidence" doesn't seem to do justice to the sheer breathtaking monumental folly of the concept. It was a politically conceived idea that the Third Republic pinned all its hopes on. horrified by the appalling slaughter of the first world war, closing its eyes completely to the fact that not only could it never have worked, it would provoke the very situation it was intended to avoid. Why anyone would suppose that the Nazi wehrmacht would respect international borders any more than the German Empire had done in 1914 is beyond any rational comprehension. THe Frencg ended up with half a wall; and with supreme irony its strength was never put to the test; the German army simply went round it.