Which agreement facilitated Germany's acceptance into the League of Nations by addressing its western borders?

The correct response highlights the Locarno Treaties, which were crucial in facilitating Germany's acceptance into the League of Nations by addressing and securing its western borders. Signed in 1925, the treaties were a series of agreements between Germany, France, Belgium, Great Britain, and Italy, designed to ensure peace in Western Europe by formalizing the post-World War I boundaries and promoting non-aggression among the signatory nations.

One of the significant outcomes of the Locarno Treaties was that Germany recognized its western borders with France and Belgium and promised not to violate these boundaries. This act of recognition helped reduce tensions in the region and built trust among European nations, ultimately contributing to Germany's admission into the League of Nations in 1926. The assurance of mutual security and respect for borders was critical in the post-war context, as it aimed to prevent future conflicts and restore Germany's status within the international community.

In contrast, the other agreements mentioned served different purposes. The Kellogg-Briand Pact was primarily a commitment to renouncing war as a means of resolving disputes. The Washington Conference focused on naval disarmament and security in the Pacific rather than European territorial issues. The Rapallo Treaty was an agreement between Germany and Soviet Russia