Parliaments and external sovereignty in representative regimes: Max Weber's contributions to the founding of the Weimar Republic

On the long run, the control over war powers has always been a stumbling block in representative regimes, especially when founded on sudden revolutions or regime collapse in wartime. At the end of the eighteen century, the French and American assemblies invented principles and institutions to ward off the spectrum of standing armies and royal prerogatives, both perceived as remnants of the previous British attempt to debunk the "Raison d'État" with the help of parliaments. At the eve of the First World War, the British, French and American parliaments had managed to obtain more influence on foreign affairs, especially through the institution of special committees and public hearings. In 1917, eager to import such devices into the German imperial regime, Max Weber published in the Frankfurter Zeitung, in the midst of the war, a long essay on the role of parliaments over foreign affairs and government in general, advocating for a stronger parliamentary control over administrative bodies (including military ones). What influence and reception had his ideas on the debates that led to the founding of the Weimar Republic? Why did he endorse in 1919 the idea of a "Reich President" with extensive powers in diplomatic and military affairs? Last, how Max Weber's contribution to the founding of the Weimar Republic can be put in a larger historical picture of representative regimes, going from the British, American and French revolutions to the founding of the German Republic of Germany in 1949 or the Fifth Republic in 1958?