He was the French Minister of Finance during World War I. Klotz was born in Paris to Alsatian Jewish parents.
In 1888, at the age of twenty, he founded Vie Franco-Russe, an illustrated paper intended to increase popular support for the Franco-Russian Alliance.
In 1895, he founded Français Quotidien, a patriotic daily paper devoted to national defense, into which Voltaire was later merged.
With no further hope of settlement, his creditors seized his Paris residence at 9 Rue de Tilsitt, which he had inherited from his brother.
His lack of financial acumen was noted years earlier by Clemenceau, who reportedly commented "My finance minister is the only Jew in Europe who knows nothing about money.