The Taliban's victory will test India, and peace in South Asia

The Taliban's blisteringly fast takeover of Afghanistan has stunned security and diplomacy experts worldwide. Days after the fall of Kabul, nations are hurriedly evacuating their diplomats and citizens, leaving behind two decades of work and investments.

The Taliban's rout is likely to cause a significant shift in the geopolitics of South Asia, and it could be particularly testing for India, given India's historically tense relations and border disputes with Pakistan and China - the two countries expected to play a crucial role in Afghanistan's future.

Pakistan shares a porous border with Afghanistan and has long been an active player in its northern neighbour's affairs. Now China is showing an interest in playing a bigger role in Afghanistan. China's foreign minister Wang Yi met with senior Taliban leaders last month.

The potential geopolitical realignments could "change things upside down", said Gautam Mukhopadhaya, India's former ambassador to Afghanistan and Syria.

Afghanistan was a loose alliance between the democratic government in Kabul, the West and other democracies like India. But the world is likely to see Pakistan, Russia, Iran and China coming together to play the next chapter of the Great Game.