This seems to mean that in order to have an effective naval defense (since we are precluded by our policy from having European allies and no South American country could give us any effective naval help) we must have on each ocean a fleet as strong as that of any nation on that ocean against whose wishes we may have to enforce a policy--or against whose policy we may have to oppose resistance.
The essential requirement of any defense is that it shall be adequate; because an inadequate defense will be broken down, while the attack will retain a large proportion of its original strength.

In the _United States Naval Institute_, in 1905, the present writer showed, by means of a series of tables, how, when two forces fight, the force which is originally the more powerful will become gradually more powerful, relatively to the weaker, as the fight goes on.

That, for instance, if two forces start with the relative powers of 10 and 8, the weaker force will be reduced so much more rapidly than the stronger that when it has been reduced to zero the stronger force will have a value of 5.69.The values mentioned indicated the actual fighting strength--strength made up of all the factors--material, physical, and psychic--that constituted it.

Of course, none of these factors can ever be accurately compared; but nevertheless the tables seemed to prove that in a contest between two forces whose total strengths are as 10 and 8 one force will be reduced to zero, while the other will be reduced not quite one-half.
One of the lessons drawn was "the folly of ineffectual resistance." Doubtless a clearer lesson would have been "the folly of ineffectual preparedness"; because, when the decision as to resistance or non-resistance is forced upon a nation, the matter is so urgent, the military, political, and international conditions so complex, and the excitement probably so intense, that a wise decision is very difficult to reach; whereas the question of what constitutes effectual preparedness is simple, and needs merely to be approached with calm nerves and an open mind.
Inasmuch as the psychic element in defense is the strongest single element, it is apparent that if the decision is reached to prepare an effectual defense the nation must be absolutely united, and must appreciate at its full value the debilitating influence of opposition to the measure; for, no matter how much money a nation may expend, no matter how many lives it may sacrifice, its defense cannot have an efficiency proportional to the effort if a considerable number of its citizens are permitted to oppose it.
In our own country there has been so much talking and writing recently about defense, that there is danger of the question coming to be considered academic; though no question is more practical, no question is more urgent.
_Defense must defend_..