The Second Sino-Indian War were a series of significant border skirmishes between India and China near the Himalayan Kingdom of Sikkim, then an Indian protectorate. These incidents began on September 11, 1967, at Nathu La and lasted until September 15. A subsequent engagement occurred at Cho La in October 1967, concluding on the same day.

In these clashes, India was able to achieve a decisive tactical advantage, effectively pushing back the attacking Chinese forces. The Indian troops managed to destroy many of the PLA fortifications at Nathu La. These clashes are particularly noted for their indication of a shift in the dynamics of China-India relations, marking a decrease in China's 'claim strength' and highlighting India's improved military performance since its defeat in the 1962 Sino-Indian War.