It is of particular importance not to confound invasion with occupation in this matter. Article 2 distinctly speaks of the _approach_ of the enemy, and thereby sanctions only such a levy _en masse_ as takes place in territory not yet _invaded_ by the enemy. Once the territory is invaded, although the invasion has not yet ripened into occupation,[122] a levy _en masse_ is no longer legitimate. But, of course, the term _territory_, as used by article 2, is not intended to mean[123] the whole extent of the State of a belligerent, but refers only to such parts of it as are not yet invaded. For this reason, if a town is already invaded, but not a neighbouring town, the inhabitants of the latter may, on the approach of the enemy, legitimately rise _en masse_. And it matters not whether the individuals taking part in the levy _en masse_ are acting in immediate combination with a regular army or separately from it.[124] [Footnote 122: Concerning the difference between invasion and occupation, see below, § 167.] [Footnote 123: See _Land Warfare_, §§ 31-32.] [Footnote 124: See _Land Warfare_, § 34.] [Sidenote: Barbarous Forces.] § 82. As International Law grew up amongst the States of Christendom, and as the circle of the members of the Family of Nations includes only civilised, although not necessarily Christian, States, all writers on International Law agree that in wars between themselves the members of the Family of Nations should not make use of barbarous forces--that is, troops consisting of individuals belonging to savage tribes and barbarous races. But it can hardly be maintained that a rule of this kind has customarily grown up in practice, nor has it been stipulated by treaties, and the Hague Regulations overlook this point. This being the fact, it is difficult to say whether the members of such barbarous forces, if employed in a war between members of the Family of Nations, would enjoy the privileges due to members of armed forces generally. I see no reason why they should not, provided such barbarous forces would or could comply with the laws and usages of war prevalent according to International Law. But the very fact that they are barbarians makes it probable that they could or would not do so, and then it would be unreasonable to grant them the privileges generally due to members of armed forces, and it would be necessary to treat them according to discretion.[125] But it must be specially observed that the employment of barbarous forces must not be confounded with the enrolling of coloured individuals into the regular army and the employment of regiments consisting of disciplined coloured soldiers. There is no reason whatever why, for instance, the members of a regiment eventually formed by the United States of America out of negroes bred and educated in America, or why members of Indian regiments under English commanders, if employed in wars between members of the Family of Nations, should not