Both Britain and Russia tried to disguise their motives even as they in fact encroached on China. Nominally they sought self-rule for Tibet and Outer Mongolia. But in fact they wanted to urge those places to declare independence only so that they could later make them into "protectorates" of their own.
英俄的侵華策略，都是「舍名取實」，名義上是爭取藏、蒙自治，實質是慫恿其獨立，而後使其成為自己的「保護國」。