This collection of essays examines the political and diplomatic roots of France's insecurity after 1870, tracing how revolutionary ideas and successive regime changes reshaped European balance by enabling the unifications of Germany and Italy. Drawing on memoirs, recent historical works, and contemporary polemics, the author analyzes the decisions of leading statesmen, criticizes France's abandonment of a traditional protective policy, and locates responsibility in a succession of errors, institutional weaknesses, and ideological shifts since the Revolution. The pieces blend historical narrative, commentary on military and diplomatic developments, and reflections on national strategy and consequence.