The Snow Lion and the British Lion continues.....

The defining principle that McMahon had followed was that the Indo-Tibet boundary should lie approximately along the edge of the Tibetan plateau, a natural and generally understood frontier between Tibet and India.

To give this more precise expression he had chosen as a guiding principle the line of the highest mountain crest-lines along the Himalayan chain, which again generally lay on or close to the edge of the Tibetan plateau.

Where such a mountain ridge did not exist near the edge of the plateau, he used the edge of the plateau itself, as at Bumla near Tawang for example, which is easily distinguishable both on a map and on the ground. This method of delimiting the border could be broadly described as the ‘line of the watershed’.

The actual line of the watershed has actually also been used where such a suitable one exists, exactly as the line described to define the Sikkim-Tibet boundary in the 1890 agreement between Britain and China. In some places it is actually so, both as marked and on the ground.

But in some places it is not easy to find or define such a watershed, because some rivers flow southwards down from the Tibetan plateau, cutting across the Himalayan range. One such example is near the disputed perceptions of the Line at Khinzemane in the Tawang tract, where the Nyamjang Chu flowing from Tibet enters the Monpa-inhabited area. Nor can any significant distinguishing feature be seen that would help in laying the boundary along a clearly-distinguishable geographical feature. The potential for disagreement, or for differing views on where a common boundary should lie, is greatest in such areas, and can only be mutually resolved, not unilaterally decided by one or the other party.

Though the Chinese Communist government of China was to term the McMahon Line the ‘illegal McMahon Line’ from the start of correspondence on this subject, they in fact did treat it as the de facto boundary, and still
do.

To be continued....