From Wealth to Power holds two different sorts of interest for the non-specialist reader. The first lies in the curious history of the United States entry into the ranks of the Great Powers. Fareed Zakaria gives a lively account of the ways in which for 25 years after the civil war the United States did not employ its growing industrial might on the international stage, and then of the ways in which from 1889-1921, it increasingly did.
The second lies in the theoretical bearings of the book: Zakaria supposes that this history demonstrates the merits of a particular theory of international relations - what he terms "state-centred realism" - but the sceptical may wonder whether it does not demonstrate the feebleness of theorising in international relations and the superiority of good narrative history to what is passed off as "theory".
The thought that animates the book is something like this. If some version of "realism" is correct, states will attempt to extend their power beyond their existing borders and to control the behaviour of other states to the degree that their resources permit.
What Zakaria takes to be "classical" realism amounts to the claim that the international political system tends to an equilibrium in which these tendencies hold each other in check. This is the view made famous by Kenneth Waltz, whose ambition was essentially to produce an account of the international "system" in which its character as a system was the main, or in some interpretations the only, explanatory consideration.
It has been criticised by the protagonists of "defensive realism", who maintain that states only extend their interests to the full extent possible when they are threatened. It is defensive realism that Zakaria wishes to demolish, and a variant on classical realism, which he defends. He complains, not unfairly, that the protagonists of defensive realism waver between claiming that states in fact extend their international interests only when threatened and claiming that they ought to behave like that, which presupposes that they do not. But it is obvious enough that a realism that simply asserts that states accumulate power in the international arena to the extent permitted by a combination of their own resources and the like behaviour of other states is vulnerable to the complaint that it is excessively coy about the motivations of politicians, about the ability of a state to convert its economic resources into diplomatic and military capacity, and about the degree of public support for foreign adventures.
Zakaria is an acute critic of much of what passes for international relations theory, noting that expansionist policies have been attributed sometimes to depression, sometimes to prosperity, sometimes to the ability of a single politician to get his own way, and sometimes to the inability of politicians to withstand pressures for expansionist action. What he is perhaps less deft at is noticing that his favoured theoretical position, what he calls "state-centred realism", is not much of a theory either. His own attempts to show that defensive realism is neither coherent nor compatible with the history of the US in the later 19th century are certainly more successful than his attempts to show that state-centred realism remains in possession of the field.
For the theory says little more than this. The history of the foreign policy of the US between the end of the civil war and 1889 falsifies any suggestion that a state that possesses abundant economic resources and substantial military capacity will use it to extend its interests abroad.
The civil war had shown that the US could put enormous resources into its armed forces; in the years after the civil war, economic growth was astonishing. Yet until the late 1880s, American foreign policy was, in contrast to the pre-civil war period and the two decades before the first world war, lacking in ambition.
The reason is to be sought, not in a sudden decline in the public taste for expanding the influence of the US, but in the inability of the governing structures to convert economic resources and military know-how into the instruments of an expansive foreign policy.
In short, resources support expansion only to the degree that the state can capitalise on those resources for the purpose. After the civil war, the government of the US could not do so, because the senate - or more specifically Senator Sumner - was determined to frustrate any plan put forward by the executive - or more specifically secretary of state Seward. This is not an implausible view and Zakaria paints a convincing picture of two levels of antagonism, personal between Seward and Sumner and institutional between congress and executive.
In Dr Zakaria's account of the matter, from the mid-1880s, the balance swung in favour of the executive branch and civil service reform began to improve the technical competence of the government. He admits that this left the US government a long way behind European governments, but argues that a modest improvement in the ability of the government to pursue any policy combined with a decisive transfer of responsibility for foreign policy to the executive, provided enough of a boost in regime capacity to permit a foreign policy that matched the country's resources.
In the background, and not much mentioned, is a long expansionist tradition: the US had its eye on most Caribbean islands for a hundred years, and many Americans hoped the entire landmass would be united under one government, based perhaps in Mexico City. It is not the inability of the American state to convert economic muscle into military and diplomatic muscle that explains why these imperial ambitions have come to seem increasingly absurd.
Zakaria mentions, though only in passing, that state-centred realism is not useful in explaining American foreign policy in the 1930s, which casts doubt on the extent to which he thinks of it as a theory in the first place.
It is a pity that someone who writes so sharply and so elegantly should have cluttered this history of an interesting period in American foreign policy with so much attention to a near-tautology when he could more usefully have discussed so many other matters.
Alan Ryan is warden, New College, Oxford.
Wealth to Power: The Unusual Origins of America's World Role
Author - Fareed Zakaria
ISBN - 0 691 04496 1
Publisher - Princeton University Press
Price - £23.00
Pages - 199