Siam (Thailand) maintained membership in the League of Nations from its inception to its demise and stood as only one of three (with Japan and China) independent East Asian members. Siam's role in the League had received little scholarly attention previously, but Stefan Hell has filled this void, arguing that membership played a significant role in bringing about treaty revision, provided Siam access to the expertise offered by League agencies, and permitted the nation's leaders to “demonstrate and reinforce [Siam's] modernity or progressiveness domestically and internationally.” (p. 13)

The study begins by explaining Siam's 1917 decision to enter World War I on the Allied side in order to gain prestige and a seat at the peace table, a move that put the country in the position to become a charter member of the League. Thai diplomats then used this elevated status as leverage in arguing for treaty revision, with the short-term goal of achieving tariff autonomy. Hell believes this strategy worked well, thanks in no small part to the quiet diplomacy of Prince Charoon, Siam's minister in Paris, who served as his nation's permanent representative to the League until his death in 1928. The Prince generally kept a low public profile in Geneva. He briefly lobbied for an open, non-permanent seat on the League Council for Siam in 1928, but the Thai were outmaneuvered by their Persian counterparts and, anticipating defeat, did not actively contest the election. As it turned out, Siam would never hold a seat on the Council, the center of power within the League.

Among the highlights of the book are profiles of key players like Prince Charoon and his more forward and outspoken successor Prince Varnvaidya (Prince Wanwaithayakorn), as well as lower-ranking commoners who served in Geneva, including two, Luang Vichit Vadhakorn (Wichit Wathakan) and Phra Sarassana (Phra Sarasat Phonlakhan), who went on to achieve notoriety in other capacities. Although in most countries diplomats then were – and often still are – representatives of traditional elites, it is harder to imagine a wider gap than that which existed between the wealthy princes who dominated Siam's diplomatic corps in the 1920s and the average citizens of the state they represented. They, like Siam's only League of Nations career bureaucrat, Mani Sanasen, had been educated in Europe and often spent most of their lives there.

The middle chapters of the book are taken up with the domestic impact of Siam's League membership on such matters of social concern as opium control, public health and human trafficking. Siam played an active role in committees dealing with these matters, even hosting the Bangkok Opium Conference of November 1931 under League auspices. Although Siam's problems in these realms were by no means solved by such participation, Hell emphasizes the good intentions of the nation's leaders and the positive effects of Siam's involvement in these international bodies. He argues that the pre-1932 coup royalists and the clique of military officers and civilian bureaucrats who overthrew them shared the goals of modernizing the country and raising the status of Siam as a “civilized” country. Both also saw membership of the League as a useful tool in achieving these goals and in strengthening their own position domestically.

The League's decline in prestige and significance in the 1930s reflected its failure to maintain collective security when confronted with a series of crises, beginning with the Manchurian Incident of 1931 which led to Japan's takeover of the area in the face of Chinese protests. Siam abstained in the vote to accept the Lytton Commission's investigatory report on the Incident, its most famous action as a League member because of subsequent assiduous Japanese attempts to portray it as a “pro-Japanese” move. Hell conclusively demonstrates that it was not intended as such, but merely reflected a longstanding desire to avoid any embroilment in international quarrels that might boomerang and endanger Siam's limited national interests.

Hell goes on to analyze subsequent Siamese support for the League sanctions against Italy after its invasion of Ethiopia in 1935 – albeit with a loophole that allowed purchase of ships for the Siamese navy – abstention in a vote related to the outbreak of the Sino-Japanese War in 1937, and a vote for the expulsion of the Soviet Union after its attack on Finland in 1939. Of greatest interest is his interpretation of the 1937 abstention as a more truly pro-Japanese act, one that reflected changing foreign policy calculations in Bangkok, particularly among military figures in the government who had begun to question the relevance of the League and saw a need to accommodate rising Japanese power in East Asia.

Hell musters ample support for his main argument that Siam's membership in the League played a more significant role in Siam's foreign policy calculations, both before and after the pivotal year of 1932, than previously recognized. However, there are no really surprising revelations in the monograph. Hell demonstrates the realistic approach of Siam's statesmen and their ability to play a weak hand with remarkable skill, a reaffirmation of a traditional view. The League's failure to maintain peace is clearly the primary reason that the institution has been somewhat neglected by historians, but others have shown, as Hell does, that the League involved itself constructively in many other areas. At the bottom line, the great strength of the book is the author's remarkably thorough research in both archival and secondary sources. The publisher also deserves a tip of the hat for producing an attractive, well-illustrated volume that, while lacking an index, features easily accessible notes placed in the side margins and useful appendices.