The Locarno treaties promised a new era of reconciliation that seemed fulfilled in the mid-to-late 1920s as the European and world economies recovered and the German electorate turned its back on extremists of the right and left. Locarno had also anticipated Germany’s entry into the League. But the prospect of expanding the League Council kicked off an indelicate scramble for Council seats as Britain supported Spain, France supported Poland, and Brazil insisted that it represent Latin America (angering the Argentines). Sweden and Czechoslovakia helped to break the deadlock by magnanimously sacrificing their seats, although Brazil in the end quit the League. Finally, on September 8, 1927, Stresemann led a German delegation into the halls of Geneva, pledging that Germany’s steadfast will was to labour for freedom, peace, and unity. Briand, by now the statesman most associated with “the spirit of Geneva,” replied in like terms: “No more blood, no more cannon, no more machine-guns! . . . Let our countries sacrifice their amour-propre for the sake of the peace of the world.” The same month, Stresemann tried to capitalize on the goodwill during an interview with Briand at Thoiry. He suggested a 1,500,000,000-mark advance on German reparations payments (to ease the French fiscal crisis then nearing its climax) in return for immediate evacuation of the last two Rhineland zones. The French chamber would likely have rejected such a concession, and in any case Poincaré, again in power, stabilized the franc soon after.

The very goodwill expressed at Geneva—and removal of the Interallied Military Control Commission from Germany in January 1927—prompted London and Washington to ask why the French (despite their pleas of penury when war debts were discussed) still maintained the largest army in Europe. France clung firm to its belief in military deterrence of Germany, even when isolated in the League of Nations Disarmament Preparatory Commission, but the German demand for equality of treatment under the League Charter impressed the Anglo-Americans. To avert U.S. suspicions, Briand enlisted Secretary Kellogg’s participation in promoting a treaty by which all nations might “renounce the resort to war as an instrument of national policy.” This Kellogg–Briand Pact, signed on August 27, 1928, and eventually subscribed to by virtually the entire world, marked the high point of postwar faith in paper treaties and irenic promises.

On July 3, 1928, Chancellor Hermann Müller (a Social Democrat) and Stresemann decided to force the pace of Versailles revisionism by claiming Germany’s moral right to early evacuation of the Rhineland. In return they offered a definitive reparations settlement to replace the temporary Dawes Plan. The French were obliged to consider the offer—a revival of Thoiry—because the French chamber had refused to ratify the 1926 agreement with the United States on war debts on the ground that it did not yet know what could be expected of Germany in reparations. So another committee of experts under another American, Owen D. Young, drafted a plan that was approved at the Hague Conference of August 1929. The Young Plan projected German annuities lasting until 1989. In return, the Allies abolished the Reparations Commission, restored German financial independence, and promised evacuation of the Rhineland by 1930, five years ahead of the Versailles schedule.

Why did Briand and even Poincaré make so many concessions between 1925 and 1929? Briand, of course, had sincerely hoped for Germany’s “moral disarmament,” and both concluded that France’s treaty rights had become a wasting asset. Better to sacrifice them now in return for concessions and goodwill, since they would expire sooner or later anyway. But Stresemann was far from accepting the status quo. His policy of accommodation was designed to achieve the gradual abolition of the Versailles strictures until Germany recovered its prewar freedom of action, at which time he could set out to restore its prewar boundaries as well. For instance, he showed no interest in an “Eastern Locarno” ensuring the boundaries of the successor states. That is not to say, however, that Stresemann anticipated the use of force or the revival of Germany’s extreme war aims.

As the decade of the 1920s came to a close, most Europeans expected prosperity and harmony to continue. Briand even went so far as to propose in 1929 that France and Germany explore virtual political integration in a European union, asking only that Germany confirm her 1919 boundaries as immutable. But Stresemann died suddenly on October 3, 1929, and three weeks later the New York stock market crashed. In the storms to come, the need for firm, material guarantees of security would be greater than ever. But on June 30, 1930, in accordance with the Young Plan, the last Allied troops departed the German Rhineland for home.