The consensus of opinion among European Powers was that the landing of troops at Beira and the passage by rail to Rhodesia with the consent of Portugal constituted a breach of neutrality on the part of the latter. The opinion was freely expressed that the British Government not only placed a strained interpretation upon the only basis for her action, the treaty of 1891, but that even upon this interpretation she possessed no real servitude over the territory used by her for warlike purposes. The only claim of justification advanced by the British Government which would appear at all tenable rests upon the statement of Calvo: "It may be that a servitude of public order, or a treaty made antecedently to the war, imposes on a neutral State the obligation of allowing the passage of the troops of one belligerent." "In such a case," Calvo concludes, "the fulfilment of the legal obligation cannot be regarded as an assistance afforded to that belligerent and a violation of the duties of neutrality."[21] [Footnote 21: Baty, Int. Law in South Africa, p. 73, quoting Calvo. But Calvo calls attention to the fact that this is his own "exception to the general rule," in support of which he cites no authorities and only one precedent--that of the passage of foreign troops across the Canton of Schaffhausen in 1867 by virtue of a prior treaty between Switzerland and the Grand Duchy of Baden. Obviously no general conclusion can be drawn from the conduct of a neutralized state, such as Switzerland. The general rule, not the exception, is sought in determining international rights. Droit international, 3d Ed., III, §2347.] Basing his argument largely upon this authority, Mr. Baty asserts that Calvo approves the granting of passage where this privilege has been secured by previous treaty. But the following statement which he cites from Calvo, taken in connection with the rule given above, would appear to deny this conclusion: "During war neutrals may oppose, even by force, all attempts that a belligerent may make to use their territory, and may, in particular, refuse one of the belligerents a passage for its armies to attack the enemy; _so much the more so, inasmuch as the neutral who should allow a passage of the troops of one belligerent would be false to its character and would give the other just cause of war."_[22] [Footnote 22: Int. Law in South Africa, p. 73. This quotation is slightly misleading, but even as used it clearly denies the English claim.]