probably the cause is that the control of the
sea, after having been held in succession by several secondary powers,
has passed into the hands of England, an insular power, rich in ships,
but without the land-forces necessary for such expeditions.

It is evident that from both of these causes the condition of things now
is very different from that existing when Xerxes marched to the conquest
of Greece, followed by four thousand vessels of all dimensions, or when
Alexander marched from Macedonia over Asia Minor to Tyre, while his
fleet coasted the shore.

Nevertheless, if we no longer see such invasions, it is very true that
the assistance of a fleet of men-of-war and transports will always be of
immense value to any army on shore when the two can act in concert.
Still, sailing-ships are an uncertain resource, for their progress
depends upon the winds,--which may be unfavorable: in addition, any kind
of fleet is exposed to great dangers in storms, which are not of rare
occurrence.

The more or less hostile tone of the people, the length of the line of
operations, and the great distance of the principal objective point, are
the only points which require any deviation from the ordinary operations
of war.

Invasions of neighboring states, if less dangerous than distant ones,
are still not without great danger of failure. A French army attacking
Cadiz might find a tomb on the Guadalquivir, although well based upon
the Pyrenees and possessing intermediate bases upon the Ebro and the
Tagus. Likewise, the army which in 1809 besieged Komorn in the heart of
Hungary might have been destroyed on the plains of Wagram without going
as far as the Beresina. The antecedents, the number of disposable
troops, the successes already gained, the state of the country, will all
be elements in determining the extent of the enterprises to be
undertaken; and to be able to proportion them well to his resources, in
view of the attendant circumstances, is a great talent in a general.
Although diplomacy does not play so important a part in these invasions
as in those more distant, it is still of importance; since, as stated in
Article VI., there is no enemy, however insignificant, whom it would not
be useful to convert into an ally. The influence which the change of
policy of the Duke of Savoy in 1706 exercised over the events of that
day, and the effects of the stand taken by Maurice of Saxony in 1551,
and of Bavaria in 1813, prove clearly the i