War is the acme of the endeavor of man.

Each side determines that it will win at all costs and at all hazards; that nobody's comfort, happiness, or safety shall receive the slightest consideration; that everybody's strength and courage must be worked to the limit by night as well as by day, and that there must be no rest and no yielding to any softening influence whatever; that the whole strength and mind of the nation, and of every individual in it, must be devoted, and must be sacrificed, if need be, to the cause at stake.
In war, a navy's primary duty has usually been to protect the coast and trade routes of its country; and in order to do this, it has had to be able to oppose to an attacking fleet a defending fleet more militarily effective.

If it were less effective, even if no invasion were attempted, the attacking fleet could cripple or destroy the defending fleet and then institute a blockade.

In modern times an effective blockade, or at least a hostile patrol of trade routes, could be held hundreds of miles from the coast, where the menace of submarines would be negligible; and this blockade would stop practically all import and export trade.

This would compel the country to live exclusively on its own resources, and renounce intercourse with the outside world.