Why did the Allies evacuate the first Rhineland zone after the Locarno agreements?

The Allies evacuated the first zone of the occupied Rhineland—the Cologne area—following the Pact of Locarno because the agreements provided the security guarantees that France had previously demanded.12

Prior to the Locarno negotiations, the French government had refused to proceed with the scheduled January 1925 evacuation of the Rhineland without tangible assurances of security. By signing the Locarno treaties in October 1925, Germany voluntarily renounced the use of force to alter its western frontiers, as established by the Treaty of Versailles, and agreed to settle disputes through arbitration.231

This move toward "moral disarmament" and the mutual guarantee of borders by Great Britain and Italy satisfied French requirements, allowing for the withdrawal of Allied troops from the first zone in 1926. This was a significant step in Gustav Stresemann's broader diplomatic effort to restore Germany's position as an equal partner in Europe.142