The Irish conscription crisis of April 1918 is familiar to historians of both World War I and the Irish independence movement. The German offensive triggered by the signing of the Brest-Litovsk Treaty in March, which permitted no less than a million German soldiers to move from Russia to the Western Front, prompted British policy makers to consider what they had avoided for the previous nearly four years of war: introducing compulsory military service in Ireland. But the threat of conscription (which had been in force in Britain itself since 1916) triggered a surge of Irish protest that contributed to Sinn Féin's startling victory in the December 1918 British elections, when the upstart party captured nearly all of the seats previously held by the Irish Parliamentary Party.

This much is widely known. Nonetheless, historians have generally seen resistance to conscription as just one small piece of the puzzle of how Sinn Féin, which sought a fully independent Ireland, so thoroughly decimated the Irish Party, with its less ambitious objective of Home Rule. After all, when the war began, Home Rule had (at least on paper) been achieved and John Redmond's party was supported by the vast majority of the Irish nationalist population. At the center of most historical interpretations for the dramatic shift in the respective fortunes of the two parties has been the 1916 Easter Rising, and especially Britain's ill-conceived executions of its leaders that followed. However, in Conscription, US Intervention and the Transformation of Ireland, 1914–1918: Divergent Destinies, Emmanuel Destenay demonstrates conclusively that although conscription was never implemented in Ireland, the fear of conscription needs to be taken more fully into account in explaining the shift. Beginning to generate popular anxieties in late 1916, he shows, the threat of compulsory military service played a central role in Sinn Féin's four by-election victories over the Irish Party in 1917. These victories allowed Sinn Féin to reorganize and set the stage for the landslide of the following year.

Anxiety about conscription dovetailed with larger international events. When Woodrow Wilson took the United States into the war in April 1917, Sinn Féin's leaders began to combine their opposition to enforced military service with a new language of national self-determination that they took directly from the American president. Meanwhile, the failure of the British-organized Irish convention of that year to implement Home Rule in the face of Unionist opposition also helped sideline the Irish Party, along with what now seemed to many as its anemic objective of limited Irish political autonomy. “All changed, changed quietly,” Destenay posits, in an elegant chapter title that significantly modifies Yeats's famous line (71).

This summary does not fully convey the sophistication of Destenay's argument or the clarity and verve of his writing. His chapter on April 1918, for example, is now probably the fullest account of the conscription crisis itself that we have. Also noteworthy is the range of Destenay's primary sources, which include previously unexamined correspondence from French consuls and ambassadors in Dublin, London, and Washington. These astute diplomatic observers of the Irish political scene act as a sort of Greek chorus throughout the entire book, bringing a fascinating new perspective to bear on the subject.

Most impressive of all is Destenay's deployment of a broad international framework for what is still often seen as a specifically Irish (or Irish-British) story. Particularly in his analysis of Sinn Féin's embrace of Woodrow Wilson's language of national self-determination, he goes farther than any previous historian in applying the argument made by Erez Manela in The Wilsonian Moment: Self-Determination and the International Origins of Anticolonial Nationalism (2007) to the Irish Revolution. It was not only independence activists in Egypt, India, Korea, and China who looked to the American president as an icon of their aspirations, Destenay forcefully demonstrates, but those in Ireland as well.

The socioeconomic dynamics of this history are perhaps not as fully developed as they might be: nationalist political leaders tend to occupy center stage in Destenay's account, while the Irish farmers and workers whose strenuous opposition to conscription was the backbone of the movement are less fully analyzed. It would have been interesting, for example, had he interrogated Paul Bew's suggestion in Ireland: The Politics of Enmity, 1789–2006 (2007) that the fight against conscription served to paper over critical socioeconomic divisions within Irish nationalism, as farmers threw their support behind Sinn Féin despite their concerns about what they saw as the party's increasingly pro-worker policies. More importantly, we will have to wait for a final verdict on Destenay's most ambitious claim: that despite the Easter Rising's status as a national foundation myth, it was the threat of conscription, not Easter Week 1916, that “decisively redirected the course of Irish history” (xiii). Whatever the final results of the debate on that claim might be, this is a book that scholars of the critical period from 1914 to 1918 will find indispensable.