But even if two States go to war with a third, they do not always both look in like measure upon this common enemy as one that they must destroy or be destroyed by themselves, the business is often settled like a commercial transaction; each, according to the amount of the risk he incurs or the advantage to be expected, takes shares in the concern to the extent of 30,000 or 40,000 men, and acts as if he could not lose more than the amount of his investment.
Not only is this the point of view taken when a State comes to the assistance of another in a cause in which it has in a manner, little concern, but even when both allies have a common and very considerable interest at stake, nothing can be done except under diplomatic reservation, and the contracting parties usually only agree to furnish a small stipulated contingent, in order to employ the rest of the forces according to the special ends to which policy may happen to lead them.
This way of regarding wars entered into by reason of alliances was quite general, and was only obliged to give place to the natural way in quite modern times, when the extremity of danger drove men’s minds into the natural direction (as in the wars against Buonaparte), and when the most boundless power compelled them to it (as under Buonaparte). It was an abnormal thing, an anomaly, for war and peace are ideas which in their foundation can have no gradations; nevertheless it was no mere diplomatic offspring which the reason could look down upon, but deeply rooted in the natural limitedness and weakness of human nature.
Lastly, even in wars carried on without allies, the political cause of a war has a great influence on the method in which it is conducted.
If we only require from the enemy a small sacrifice, then we content ourselves with aiming at a small equivalent by the war, and we expect to attain that by moderate efforts. The enemy reasons in very much the same way. Now, if one or the other finds that he has erred in his