But the number of troops that may be brought into the field in times of great emergency is, of course, much greater than can be supported during a long war, or as a part of a permanent military establishment. Montesquieu estimates that modern nations are capable of supporting, without endangering their power, a permanent military force of about one-hundredth part of their population. This ratio differs but little from that of the present military establishments of the great European powers.
Great Britain, with a population of about twenty-five millions, and a general budget of $250,000,000, supports a military and naval force of about 150,000 effective and 100,000 non-effective men, 250,000 in all, at an annual expense of from seventy to eighty millions of dollars.
Russia, with a population of about seventy millions, supports an active army of 632,000 men, with an immense reserve, at an expense of about $65,000,000, out of a general budget of $90,000,000; that is, the expense of her military establishment is to her whole budget as 7 to 10.
Austria, with a population of thirty-five millions, has an organized peace establishment of 370,000, (about 250,000 in active service,) and a reserve of 260,000, at an expense of $36,000,000, out of a general budget of $100,000,000.
Prussia, with a population of about fifteen millions, has from 100,000 to 120,000 men in arms, with a reserve of 200,000, at an annual expense of more than $18,000,000, out of a general budget of about $38,000,000.
France, with a population of near thirty-five millions, supports a permanent establishment of about 350,000 men, at an expense of seventy or eighty millions of dollars, out of a total budget of $280,000,000. France has long supported a permanent military force of from one-hundredth to one hundred-and-tenth of her population, at an expense of from one-fourth to one-fifth of her whole budget. The following table, copied from the "Spectateur Militaire," shows the state of the army at six different periods between 1788 and 1842. It omits, of course, the extraordinary levies of the wars of the Revolution and of the Empire.
Table.
| Dates. | Population. | Budget of State. | Budget of Army. | Army, Peace Establisment. Men | Army, War establishment. Men | Remarks |
| 1788 | 24,000,000 | livres 500,000,000 | livres 100,000,000 | 180,000 | 300,000 | |
| 1814 | 28,000,000 | francs 800,000,000 | francs 180,000,000 | 255,000 | 340,000 | Ordinance of 1814 |
| 1823 | 31,000,000 | 900,000,000 | 200,000,000 | 280,000 | 390,000 | Report of Minister of War |
| 1830 | 32,000,000 | 1,000,000,000 | 220,000,000 | 312,000 | 500,000 | Report of Minister of War |
| 1840 | 34,000,000 | 1,170,000,000 | 242,000,000 | 312,000 | not shown | Budget of 1840. |
| 1842 | 35,000,000 | 1,200,000,000 | 285,000,000 | 370,000 | 520,000 | Estimated expences of 1842 |
From these data we see that the great European powers at the present day maintain, in time of peace, military establishments equal to about one-hundredth part of their entire population.
The geographical position of a country also greatly influences the degree and character of its military preparation. It may be bordered on one or more sides by mountains and other obstacles calculated to diminish the probability of invasion; or the whole frontier may be wide open to an attack: the interior may be of such a nature as to furnish security to its own army, and yet be fatal to the enemy should he occupy it; or it may furnish him advantages far superior to his own country. It may be an island in the sea, and consequently exposed only to maritime descents—events of rare occurrence in modern times.