China and India have a long history of territorial disputes along their shared border. Beijing says India has undermined China's territorial sovereignty by revoking Article 370 unilaterally.
In a slew of government orders, India's Hindu nationalist government embarked on the highly controversial process of scrapping a law key to the Kashmir accession treaty and carving two union territories out of the state: Jammu and Kashmir and Ladakh.
This unilateral decision to revoke Article 370 has sent shock waves across the world and rattled not only Pakistan, but also China.
In a press briefing, Chinese Foreign Ministry Spokesperson Hua Chunying, said: "Recently India has continued to undermine China's territorial sovereignty by unilaterally changing its domestic law. Such practice is unacceptable and will not come into force."
But what is at stake for China in Kashmir?
Nestled in the picturesque Himalayas, the restive region of Kashmir is divided between three countries: India, Pakistan, and China.
While India controls Muslim-majority Jammu and Kashmir which until now was a state, Pakistan exercises authority over two areas, Pakistan-administered Kashmir and Gilgit-Baltistan.
The Asian rivals have engaged in direct hostilities over border disputes in the past. In a bloody 1962 war, India lost a sliver of Kashmir called Aksai Chin to China, which Beijing then merged into its Xinjiang Uyghur Autonomous Region.
Skirmishes began in 1958 when China published a map showing the Aksai Chin plateau on its western stretch of border as part of its territory.
This was vehemently opposed by India and the dispute escalated into a full-blown war.
Heavy fighting took place on October 10, killing 25 Indian troops and 33 Chinese soldiers. On October 20, Chinese troops overran Indian military positions in Aksai Chin. Within two days, China had seized the entire territory.
After a three-week ceasefire, the war resumed on November 14, 1962, with an Indian attack against the Chinese position at Walong. Hundreds lost their lives.
The two warring sides then declared a formal ceasefire on November 19, under international pressure.
China withdrew to pre-war positions behind the McMahon line dividing the two countries along Arunachal Pradesh. The ceasefire line became known as the Line of Actual Control (LAC).
In 1963, Pakistan and China exchanged border territories. The deal passed another stretch of Kashmir called Shakasgam valley into Chinese hands.
When India’s Home Minister Amit Shah announced a resolution over changes in Article 370 earlier this week, he said:"Kashmir is an integral part of India, there is no doubt over it. When I talk about Jammu and Kashmir, Pakistan occupied Kashmir and Aksai Chin are included in it." A comment that infuriated Beijing.
The two countries are also at loggerheads over Arunachal Pradesh: India considers the area one of its northeastern states, while China stakes claim to about 90,000 square kilometres, calling it a part of southern Tibet.
Beijing has always expressed its displeasure over Indian dignitaries visiting the disputed area reiterating it has never recognised the sensitive border state and that India should refrain from any action that may ‘complicate the boundary question’.
In 2017, Indian and Chinese troops faced off at yet another bone of contention, the Doklam plateau near the Sikkim-Bhutan-Tibet trijunction. The area is claimed by both China and by India's ally Bhutan.
The dispute began in June when Chinese troops started building a road on the plateau which gets them dangerously close to a tiny stretch of Indian land known as the ‘Chicken’s Neck’ that connects India with its northeastern states.
India deployed troops to stop the project. There were hand to hand clashes but no armed skirmishes. A crisis was averted in August when the two nuclear-armed nations pulled back.
India is also concerned about the China-Pakistan Economic Corridor (CPEC) that passes through Gilgit-Baltistan administered by Pakistan.
Though Beijing says the flagship project of its Belt and Road Initiative (BRI) is a strictly economic one, devoid of any political implications, India thinks CPEC is a violation of its sovereignty.