What Calvo says is:  “Tous les publicistes sont d’accord pour admettre que le territoire d’une nation constitue une veritable propriete ... le territoire neutre doit etre a l’abri de toutes les entreprises des belligerants de quelque nature qu’elles soient; les neutres ont le droit incontestable de s’opposer par tous les moyens en leur pouvoir, meme par la force des armes, a toutes les tentatives qu’un belligerant pourrait faire pour user de leur territoire."[23] He also calls attention to the fact that Grotius, Wolff and other authors held that a belligerent, “dont la cause est juste peut, pour aller a la rencontre de son ennemi, traverser avec ses armees le territoire d’une nation neutre."[24] But his statement of the modern rule is conclusive:  “Par contre, Heffter, Hautefeuille, Manning et d’autres auteurs modernes se sont avec juste raison eleves contre des principes dans lesquels ils entrevoient la negation implicite des droits et des devoirs stricts de la neutralite.  A leur yeux, la nation neutre qui consent au passage des troupes de l’une des parties belligerantes manque a son caractere et donne a l’autre partie un juste motif de lui declarer la guerre."[25]

[Footnote 23:  Calvo, Sec.2344.]

[Footnote 24:  Ibid., Sec.2345.]

[Footnote 25:  Ibid., Sec.2346.]

Mr. Baty, without reaching any definite conclusion in the matter, admits that the point to be decided in any case is not so much the fact that there is an antecedent treaty, as the nature of that treaty.  He says, “If it granted a real right of way of the nature of a right in rem there is no reason why the way should be stopped against troops any more than why a purchaser of territory should be debarred from using, it as a base of military operations.”  But he points out, “If the treaty only created a right in personam the case is different.”  In the latter case it is obvious that the power which claims the way depends entirely on the promise of the territorial power for the exercise of that advantage.  “In such a case,” he concludes, “it may well be that the performance of its promise by the territorial power becomes unlawful, on the outbreak of war between the promiser and a third party."[26] For international purposes the true test is, “Could the power claiming the right of way, or other servitude, enforce its claims during peace time by force, without infringing the sovereignty of the territorial power?” Mr. Baty’s opinion is that “if it could, and, if the servitude is consequently a real right,” the promisee might use its road in time of war, and the owner of the territory would be “bound to permit the use, without giving offense to the enemy who is prejudiced by the existence of the servitude."[27] But he continues, “If the right of way is merely contractual, then the fulfillment of the promise to permit it must be taken to have become illegal on the outbreak of war and the treaty cannot be invoked to justify the grant of passage.”  It is