Caldwell cuts to shreds the conventional wisdom of the "immigrationist" ideology - the view that mass immigration is inevitable and in any case a necessary injection of youth into our ageing continent. He shows, contrary to the immigrationists, that the flows of recent decades are unprecedented. He also demolishes the economic and welfare- state arguments for mass immigration and points out that in most countries there was no desperate need for extra workers in the 1950s - in Britain's case, Ireland still provided a reserve army of labour.
One of the most startling figures in the book is that the number of foreign residents in Germany rose from 3 million to 7.5 million between 1971 and 2000 but the number of employed foreigners stayed the same at 2 million.
Caldwell is at his best describing the confused cultural and intellectual condition of much of Europe at the time the first waves of immigrants were arriving. It was hard, he points out, to follow Europe's rules and embrace its values when Europeans themselves were rewriting those rules and reassessing those values. After the brutal experiences of the first part of the 20th century - two world wars, the Holocaust and de-colonisation - European elites had embraced a liberal universalism that declared the moral equality of all people and implicitly questioned the legitimacy of most racial and gender hierarchies.Liberal universalism could, in theory, have been compatible with confident nation states and national identities, but in practice it seldom was. The idea of national traditions and solidarities came to be scorned by liberals in many European countries.
Caldwell reverses the conventional argument, which says that if immigration has been a relative failure it is because the host society has been too hostile and unaccommodating. On the contrary, he argues, it is because most of the host societies were too weak and insecure to make newcomers an offer that was sufficiently confident to secure their loyalty and integration. Most European countries, constrained by liberal universalism and the immigrationism ideology, were simply too laissez-faire towards migrants. For the first time in modern history, European societies were set up to allow a big group of citizens to lead their lives as if in a foreign culture..