Relations between India and China have been tense over the past few months, as the two armies faced-off against each other along their disputed border in the Himalayan region.
In 400 words, here is all the important background to help you understand what is going on.
What is the source of tension?
The root cause lies in unresolved border disputes. Sharing a border of more than 3,440km (2,100 miles), the two have overlapping territorial claims.
Their armies also come face to face at many points because the border is poorly demarcated. Rivers, lakes and snowcaps mean the line separating soldiers can shift and they often come close to confrontation.
The two are also racing to out-build each other along their disputed border. A new road to a high-altitude Indian forward air base is said to have been one of the main triggers for a clash with Chinese troops in June that killed at least 20 Indian soldiers.
The two countries have fought only one war, in 1962, when India suffered a humiliating defeat.
How bad is the situation?
Very, with this year being particularly bad. Tensions spiked in June, when clashes with Chinese troops left at least 20 Indian soldiers dead.
Relations have continued to deteriorate since then.
In August, India accused China of provoking military tensions at the border twice within one week. Both charges were denied by China, which said that the stand-off was "entirely" India's fault.
In early September, China accused India of firing shots at their troops. India denied the allegations, and accused China of firing into the air amid the stand-off.
The allegations of firing, if true, will be the first time in 45 years that shots have been fired at the border, breaking an agreement that barred firearm use.
Has the Modi-Xi 'bromance' fizzled?
Recent tensions appear to have undone the strengthening of ties led by India's PM Narendra Modi and Chinese President Xi Jinping. The two have met 18 times since Mr Modi was first elected in 2014.
But now there is also an economic fallout. Anti-China sentiment in India led to the government banning more than 150 China-linked apps, including the hugely popular TikTok and PUBG.
Officials said the move would ensure the "safety" of "Indian cyberspace". And in June, India's cricket board dropped Chinese smartphone company Vivo as the title sponsor in its upcoming cricket league.
While the two emerged as global powerhouses more than two decades ago, China has raced ahead, evident in its superior military might. But India doesn't seem to be backing down, and analysts fear this could further escalate tensions.