In the Commons debate on the treaty on 18 November 1925, Chamberlain called Locarno ‘the beginning, and not the end, of the noble work of appeasement in Europe’. Would his emphatic prediction be borne out not only by his own actions but also the general evolution of international politics in the latter 1920s? Can British policy after Locarno indeed be characterised as an overall successful bid to promote further Franco-German détente and European tranquillity, pursued until overtaken by the Great Depression? Or was it as flawed and futile as the original promotion of the security pact? Did Chamberlain ultimately fail to fulfil his mission as ‘honest broker’, especially in the critical fields of collective security and disarmament?

This analysis seeks to illuminate Britain's post-Locarno policy both from a different angle and through a wider lens. To gauge the extent of what Chamberlain's ‘noble’ policy of appeasement could achieve after Locarno, and what it could not achieve, it is not only imperative to re-assess which aims or strategies he pursued. At least as important is to explore whether, without America's political support, Britain indeed had the power – and, as Chamberlain claimed, the wherewithal – to fulfil his chosen mission: to become the main arbiter propelling Franco-German accommodation and expanding European stability to the east.

As in the American case, the domestic dimension of British foreign policymaking became increasingly important in the latter 1920s.