One of the lessons Marrku Ruotsila invites us to draw from his work is that ‘devout belief’ concerning political projects, although often commingled with nationalism, racism, antisemitism, sexism and so on, may of its own religious and theological self drive men to political conclusions, and that the historian must therefore render it the respect it deserves. (But is there ever such a thing as an unmixed motive?) The American religious groupings or tendencies upon which his searchlight has played are the ‘dispensational premillennialists’, convinced by their singular reading of the Scriptures that the world has to go – for some, was actually going – through the time of tribulations prophesied as a necessary prelude to Christ's Second Coming; ‘confessional Calvinists’ who were only interested in political authority if they and their kind could run it; and – this surprised him – ‘the majority of American Lutherans’ who proved very touchy about the ‘mixing of secular and religious competencies’. These extreme points of view matched, and indeed were articulated in opposition to, the theological liberalism of the Modernists and the ‘Social Gospel’ which some of them projected into the international sphere, writing of ‘Christianising international relations’ and finding in President Woodrow Wilson's League of Nations an instrument for the realisation of Christ's kingdom on earth. Of course the battle between the Conservatives and the Modernists was joined well before 1900, but it was the prospect and promise of the League that brought its political dimension to a climax. Should the United States ratify the Versailles Treaty and join the League or not? Ruotsila allows that Conservatives' motives now became very mixed, as the League's political opponents in the Senate and media borrowed from the theologians' arguments, and the theologians were apparently happy for them so do so. These colossal debates and the energies that they evoked have left their mark. The final chapter brings the story briskly up to date, with the ultra-evangelicals cheering the neo-conservatives' scorn for American involvement in international organisations and treaties. Ruotsila's exposition includes plenty of telling citations from the many manuscripts, books and periodicals he has scanned, and it is noteworthy that, although evidently Finnish and on the faculties of two Finnish universities, he writes better English than many of us British and American writers. Until that final chapter, where his distaste for Pat Robertson and his like is unconcealed, he maintains a fine impartiality. But has he noticed that the Conservative Evangelicals, in one respect anyway, have had the last laugh? It was impractical of them to argue that codes of principles like the Covenant of the League, the UN Charter and the Universal Declaration of Human Rights could not succeed unless they were wholly Christian in content; but recent history has vindicated their prediction that amalgams of all faiths and none would lack the substance for standing firm under strain.