Sun-tzu, by Michael I. Handel, claims boldly that ‘Jomini has traditionally been assumed
to represent the positivistic if not mechanical approach to the study of warfare, but a
careful comparison of Jomini’s work with those of Sun Tzu and Clausewitz indicates
that these three strategists are mostly in agreement on the fundamental issues’ (Handel,
2001: 3).
Clausewitz’s theory of war is considered here from two broad perspectives: what he
has to say about the relationship between politics and war; and then on the nature of war
itself. It may be important at this juncture to restate exactly why a book on the strategic
history of the past two centuries requires a discussion of strategic theory. The tersest
explanation is that everything strategic in the history of those 200 years was governed
by Clausewitz’s theory. That is a highly imperial, perhaps hegemonic, claim. To a degree
not even approached by any other theorist, Clausewitz unravelled the complexities of
war and strategy. He provided the soundest education available to anyone who wished
to understand how and why those activities function. It is probably true to argue that
without a firm grasp of Clausewitzian theory one cannot analyse strategic behaviour
properly. The strategic history in this book is not simply a narrative – an exercise that
may tell the story well enough but would yield little understanding of the reasons for, or
the consequences of, strategic events. In short, Clausewitz rules all of strategic history:
the past, the present and the future.
The first perspective to be probed is the Clausewitzian dictum on the indissoluble link
between politics, meaning policy, and war. He insists that ‘the only source of war is
politics’ and that ‘war is simply a continuation of political intercourse, with the addition
of other means’, then argues that ‘policy converts the overwhelmingly destructive
element of war into a mere instrument’ and that ‘If war is part of policy, policy will deter-
mine its character’ (Clausewitz 1976: 605–6). Clausewitz was not confused about the
nature of war, at the heart of which lies the distinguishing feature of organized violence.
In some contrast to the modern theory of strategic coercion that envisages a ‘diplomacy
of violence’ (Schelling, 1966), Clausewitz demands that war’s unique nature be treated
with respect. War may be a political instrument, first and last, but, in his word, it has its
own ‘grammar’. He warns clearly enough that although politics must always hold
sovereign sway over warfare, ‘That, however, does not imply that the political aim is a
tyrant’. He proceeds to explain that:
It [the political aim] must adapt itself to its chosen means, a process which can
radically change it; yet the political aim remains the first consideration. Policy, thus,
will permeate all military operations, and in so far as their violent nature will admit,
it will have a continuous influence on them.
(Clausewitz, 1976: 8 7)There are potent caveats in that passage. Having declared that war is a ‘continuation of
political activity by other means’, Clausewitz goes on to argue that ‘War in general, and
the commander in any specific instance, is entitled to require that the trend and design of
policy shall not be inconsistent with these means’. He allows that ‘That, of course, is no
small demand; but however much it may affect political aims in a given case, it will never
do more than modify them’ (p. 8 7). Lest his point remains obscure to some readers, he
resorts to the most direct language in order to preclude misunderstanding, or so he must
22 War, peace and international relations