[Sidenote: The neutral must guard its inviolable frontiers. It must intern the Trespassers.]
2. If the frontiers of the neutral State march with those of the territory where the War is being waged, its Government must take care to occupy its own frontiers in sufficient strength to prevent any portions of the belligerent Armies stepping across it with the object of marching through or of recovering after a Battle, or of withdrawing from War captivity. Every member of the belligerent Army who trespasses upon the territory of the neutral State is to be disarmed and to be put out of action till the end of the War. If whole detachments step across, they must likewise be dealt with. They are, indeed, not prisoners of War, but, nevertheless, are to be prevented from returning to the seat of War. A discharge before the end of the War would presuppose a particular arrangement of all parties concerned.
If a convention to cross over is concluded, then, according to the prevalent usages of War, a copy of the conditions is to be sent to the Victor.[111] If the troops passing through are taking with them prisoners of War, then these are to be treated in like fashion. Obviously, the neutral State can later demand compensation for the maintenance and care of the troops who have crossed over, or it can keep back War material as a provisional payment. Material which is liable to be spoilt, or the keeping of which would be disproportionately costly, as, for example, a considerable number of horses, can be sold, and the net proceeds set off against the cost of internment.
[Sidenote: The “sinews of war”--loans to belligerents.]
3. A neutral State can support no belligerent by furnishing military resources of any kind whatsoever, and is bound to prevent as much as possible the furnishing of such wholesale on the part of its subjects. The ambiguity of the notion “Kriegsmittel” has often led to complications. The most indispensable means for the conduct of a War is money. For this very reason it is difficult to prevent altogether the support of one or other party by citizens of neutral States, since there will always be Bankers who, in the interest of the State in whose success they put confidence, and whose solvency in the case of a defeat they do not doubt, will promote a loan. Against this nothing can be said from the point of view of the law of nations; rather the Government of a country cannot be made responsible for the actions of individual citizens, it could only accept responsibility if business of this kind was done by Banks immediately under the control of the State or on public Stock Exchanges.