The discussion of their respective merits naturally led to an inquiry
into what the alternative policies really meant. But inasmuch as the
Foreign Office committee found itself able to agree in recommending some
form of League of Nations, the idea of the Balance of Power was not
subjected to so close a scrutiny or so searching an analysis as would
certainly have been the case had the committee realised the possibility
that reaction against an imperfect League of Nations might bring once
more to the front the idea of the Balance of Power. The fact was,
however, elicited that the Foreign Office conception of the Balance of
Power is a conception erroneously supposed to have been expressed by
Castlereagh at the time of the Congress of Vienna, and adopted as the
leading principle of nineteenth century British foreign policy.
Castlereagh was not, of course, the author of the phrase or of the
policy. The phrase can be found before the end of the seventeenth
century; and in the eighteenth the policy was always pleaded by
potentates and Powers when on the defensive, and ignored by them when in
pursuit of honour or vital interests. But Castlereagh defined it afresh
after the colossal disturbance of the balance which Napoleon effected;
and he explained it as "a just repartition of force amongst the States
of Europe." They were, so to speak, to be rationed by common agreement.
There were to be five or six Great Powers, whose independence was to be
above suspicion and whose strength was to be restrained by the jealous
watchfulness of one another. If any one State, like France under
Napoleon, grew too powerful, all the rest were to combine to restrain
it.
Now, there is a good deal in common between Castlereagh's idea and that
of the League of Nations. Of course, there are obvious differences.
Castlereagh's Powers were monarchies rather than peoples; they were
limited to Europe; little regard was paid to smaller States, whose
independence sometimes rested on no better foundation than the inability
of the Great Powers to agree about their absorption; and force rather
than law or public opinion was the basis of the scheme. But none of
these differences, important though they were, between Castlereagh's
Balance of Power and the League of Nations is so fundamental as the
difference between two things which are commonly regarded as identical,
viz., Castlereagh's idea of the Balance of Power and the meaning which
has since become attached to the phrase. There are at least two senses
in which it has been used, and the two are wholly incompatible with one
another. The League of Nations in reality resembles Castlereagh's
Balance of Power more closely than does the conventional notion of that
balance; and a verbal identity has concealed a real diversity to the
confusion of all political thought on the subject.
Castlereagh's Balance of Power is what I believe mathematicians call a
multiple balance. It was not like a pair of scales, in which you have
only two weights or forces balanced one against the other. It was rather
like a chandelier, in which you have five or six different weights
co-operating to produce a general stability or equilibrium. In
Castlereagh's scheme it would not much matter if one of the weights were
a little heavier than the others, because there would be four or five of
these others to counterbalance it; and his assumption was that these
other Powers would naturally combine for the purpose of redressing the
balance and preserving the peace. But a simple balance between two
opposing forces is a very different thing. If there are only two, you
have no combination on which you can rely to counteract the increasing
power of either, and the slightest disturbance suffices to upset the
balance. Castlereagh's whole scheme therefore presupposed the continued
and permanent existence of some five or six great Powers always
preserving their independence in foreign policy and war, and
automatically acting as a check upon the might and ambition of any
single State.