I have long thought that the sudden collapse of France in 1940 was one of the most significant events of the C20th. Among the many factors which led to this unexpected event was the Crisis of 6 February 1934
https://en.wikipedia.org/wiki/6_February_1934_crisis
https://en.wikipedia.org/wiki/6_February_1934_crisis
The antiparliamentary rioting by right-wingers did not in itself threaten the Republic but it did reveal the paralysing division within the country and the contempt of many for a corrupt system. Which is why few, Left or Right, were willing to die for that Republic in June 1940
As I once wrote on my *other* blog a society where the plurality of native born citizens do not share enough of a national myth between them to make them willing to stake their lives on defending that nation is a society doomed to destruction. https://thoughtfullydetached.wordpress.com/2017/07/09/citizens-of-nowhere/