In foreign navies the need for getting information in defiance
of an enemy's attempts to prevent it, and to drive off the armed
scouts of an enemy, has been one of the prime reasons for developing
"battle cruisers," that combine the speed of the destroyer with
the long steaming radius of the battleship, a battery almost as
strong, and a very considerable protection by armor.

The aeroplane and the air-ship are recent accessions to the list of
fighting craft. Their rôle in naval warfare cannot yet be defined,
because the machines themselves have not yet reached an advanced
stage of development, and their probable performance cannot be
forecast. There is no doubt, however, in the minds of naval men
that the rôle of aircraft is to be important and distinguished.




CHAPTER III

NAVAL POWER

Mahan proved that sea power has exercised a determining influence on
history. He proved that sea power has been necessary for commercial
success in peace and military success in war. He proved that, while
many wars have culminated with the victory of some army, the victory
of some navy had been the previous essential. He proved that the
immediate cause of success had often resulted inevitably from another
cause, less apparent because more profound; that the operations of
the navy had previously brought affairs up to the "mate in four
moves," and that the final victory of the army was the resulting