China has hidden the fact that the government of Tibet did not sign the very document, the Sikkim-Tibet treaty of 1890, which Beijing is showing to support its claim over the disputed Doklam plateau.

The ongoing border stand-off was triggered after Chinese troops started building a road in Doklam, which is also claimed by Bhutan, on June 16.

Leave aside 1890, China did not agree to a treaty on the Bhutan-Tibet and Sikkim-Tibet borders until as late as 1960. This was another fact that China did not mention when it went about using the 1980 document as the basis of its claim over Doklam, analysts said.

"The Tibetan government refused to acknowledge the 1890 Convention because they were not informed or made a party to it," said Claude Arpi, historian, and Tibetologist.

Tibetan and British troops had clashed a couple of years before, and this could be the reason why the Tibetan government did not acknowledge the treaty, Arpi said.