In mid-June, Indian troops crossed into China at the Sikkim section of the border, instigating a standoff with Chinese troops. This is arguably the biggest crisis facing the two countries since the 1962 border war, because there is still no sign of the Indian troops ending their trespass into Chinese territory.

The Sikkim section of the China-India boundary was delimited in 1890 in the Convention Between Great Britain and China Relating to Sikkim and Tibet, and the boundary demarcation is recognized by both China and India.

However, India claims that a road being constructed by Chinese troops in Chinese territory has "serious" security implications for India. It fears it will lead to the severing of the so-called chicken's neck - the 20-kilometer-wide corridor that links the Indian mainland to its northeastern states. As a result, New Delhi decided to make a "preemptive" move.