To understand what happens next in Afghanistan, look to its neighbours | Mohammad Ali Shabani

In the vacuum left by the US, regional politics between Iran, UEA, Qatar and Saudi Arabia is bound to become more messy

As the US military finally leaves Afghanistan after 20 years, all eyes are rightly on the human tragedy and the political implications of the Taliban's return to power. But to understand what may come next for both Afghanistan and the world, more attention needs to be paid to the tectonic shifts in the Arab and Iranian involvement in Afghanistan since the US-led invasion in 2001. Unless the regional contests for influence are accompanied by substantive and inclusive dialogue between these actors, turmoil will only increase for the country.

Iran's changing role is a case in point. Tehran was once eager to get rid of the Taliban. In 1998, the killing of diplomats at the Iranian consulate in Mazar-i-Sharif almost ignited a war. The murders took place in the chaos of the Taliban's capture of the northern Afghan city. Tehran thus put the blame on the Taliban, which in turn pinned it on rogue elements. So it was unconventional - but certainly not odd - when Iran and the US emerged as implicit partners against the Taliban in the aftermath of the September 11 attacks. Tehran and Washington jointly backed the Northern Alliance - an alliance of warlords that held 10% of Afghanistan - as an anti-Taliban force.