We should bring a lesser calamity upon ourselves by abolishing our quarantine system against the importation of deadly disease and inviting a visitation like the great London Plague, or by letting in the Black Death to sweep our country as it swept Europe in the Middle Ages, than by neglecting our quarantine against war, as we are neglecting it, thereby inviting the pestilence of invasion. Self-preservation is the first law of Nature, and this law applies to nations exactly as it applies to individuals. Our American Republic cannot survive unless it obeys the law of survival, which all individuals must obey, which all nations must obey, and which all other nations are obeying. No individual, and no nation, has ever disobeyed that law for long and lived; and it is too big a task for the United States of America. It is the aim of this work to discover truth to the reader, unvarnished and unembellished, and, at the same time, as far as possible, to avoid personalities. Wherever practicable, philosophic generalizations have been tied down to actualities, based upon experiential knowledge and innate common-sense of the eternal fitness of things. The strong appeal of Lord Roberts for the British nation to prepare for the Armageddon that is now on, which he knew was coming, did not awaken England, but served rather to rouse Germany. Admiral Mahan pleaded long with his country for an adequate navy. All the Great Powers of the world except America were stimulated by his logic to strengthen their navies. The beautiful, imaginative, logical language of General Homer Lea, on America's military weakness, in his "Valor of Ignorance" and "The Day of the Saxon," has caused many a gun to be made, many a battalion of troops to be enlisted, and many a warship to be built--in foreign countries. The eloquent words of wisdom of Lord Roberts, Admiral Mahan, Homer Lea, and all real friends of peace and advocates of the only way of maintaining peace--by being prepared against war--have fallen on a deaf America. I am well aware of the fact that nothing I can say will rouse the people of my country to the reality and magnitude of their danger, and to a true appreciation of the imperative necessity for immediate preparation against war. Possibly this book may lessen a little the effect of the pernicious propagandism of the pacifists--may somewhat help Congressional appropriations for defense--may place a few more men and a few more guns on the firing-line, and thereby save the lives of a few of our people--may save a few homes from the torch--may lessen the area of devastation--may, by adding a little power to our resistance, help to get slightly better terms from the conquerors for our liberation.