ssentials are to secure a general who is
both a statesman and a soldier; to have clear stipulations with the
allies as to the part to be taken by each in the principal operations;
finally, to agree upon an objective point which shall be in harmony with
the common interests. By the neglect of these precautions, the greater
number of coalitions have failed, or have maintained a difficult
struggle with a power more united but weaker than the allies.

The third kind of intervention, which consists in interfering with the
whole force of the state and near to its frontiers, is more promising
than the others. Austria had an opportunity of this character in 1807,
but failed to profit by it: she again had the opportunity in 1813.
Napoleon had just collected his forces in Saxony, when Austria, taking
his front of operations in reverse, threw herself into the struggle with
two hundred thousand men, with almost perfect certainty of success. She
regained in two months the Italian empire and her influence in Germany,
which had been lost by fifteen years of disaster. In this intervention
Austria had not only the political but also the military chances in her
favor,--a double result, combining the highest advantages.

Her success was rendered more certain by the fact that while the theater
was sufficiently near her frontiers to permit the greatest possible
display of force, she at the same time interfered in a contest already
in progress, upon which she entered with the whole of her resources and
at the time most opportune for her.

This double advantage is so decisive that it permits not only powerful
monarchies, but even small states, to exercise a controlling influence
when they know how to profit by it.

Two examples may establish this. In 1552, the Elector Maurice of Saxony
boldly declared war against Charles V., who was master of Spain, Italy,
and the German empire, and had been victorious over Francis I. and held
France in his grasp. This movement carried the war into the Tyrol, and
arrested the great conqueror in his career.

In 1706, the Duke of Savoy, Victor Amadeus, by declaring himself hostile
to Louis XIV., changed the state of affairs in Italy, and caused the
recall of the French army from the banks of the Adige to the walls of
Turin, where it encountered the great catastrophe which immortalized
Prince Eugene.

Enough has been said to illustrate the importance and effect of these
opportune interventions: more illust