Iranian media reports that Iran is establishing explicitly Iran-backed Shia militias in western Afghanistan. Iran wants to protect the Shia minority (about 20 percent of Afghans) from the expanding reach of the Taliban. In the late 1990s the Taliban went after Afghan Shia in a big way and the victims have not forgotten. The new militias are composed of combat experienced Afghan Shia who served as Iranian mercenaries and survived combat in Syria. Oddly enough the name of these militias, Hashd Al Shi’I, does not use one of the local languages (Pushtun or Dari), but a language the Syrian veterans learned a little of in Syria. Hashd Al Shi’I is Arabic for “Shia Mobilization”.
Over 50,000 Afghan Shia served in Syria and, as they returned to Afghanistan, often took the initiative in protecting fellow Shia from increasing violence by Islamic terror groups, including the Taliban. The former mercs asked Iran for help but until now all Iran was willing to do was back anti-Pakistan Taliban factions that, in return for weapons and other aid from Iran, promised to leave Afghan Shia alone. Moving on to explicitly Iran-backed Shia militias is not considered a big surprise.
In 2019 Iran sent most of the Afghan mercenaries in Syria home because the revived American economic sanctions had greatly reduced the amount of money that could be spent on the war in Syria. Iran began building a new mercenary force by hiring Syrians. The best of the Iranian foreign Shia were the Afghans but there was a limited supply of Afghan Shia willing to serve as Iranian mercs in faraway Syria. To entice the Afghans to volunteer they were paid more than other foreign Shia in Syria. While the Afghans were the best fighters, a growing number would not renew their contracts and returned to Afghanistan or Iran, where mercenary service also earned an Iran residency permit. While the Syrian Arab mercs are cheaper, they are adequate. The low cost is largely because of the bad shape the Syrian economy is in and the dire poverty many Syrians live with.
By 2020 there were over 10,000 Syrian mercs in service for Iran. Most were based on or near the Israeli or Jordanian borders. Many Syrians see the Iranians and their Syrian mercs as another foreign occupation force. Syrians are tired of war while the Iranians want more of it, mainly against Israel.
Iran appreciated the efforts of the Afghan Shia in Syria. In early 2018 Iranian media reported that Afghan mercenaries working for Iran in Syria suffered over 10,000 casualties since 2013. Over 20 percent of the casualties were fatal. It was also reported that over 3,000 Afghan Shia mercenaries died fighting against Iraq in the 1980s.
The Iranian mercenary force in Syria was a decisive factor in keeping the Syrian security forces from being completely destroyed. Many of the Afghan mercs who earned residency permits in Iran did not use them because of declining economic conditions in Iran and better prospects back in Afghanistan. In Afghanistan the Syrian vets were highly respected and the Afghan government feared that those former mercs would turn into another warlord army, like the ones that tore Afghanistan apart in the 1990s. That was half right, but the commander of this new Afghan Shia force is Iranian, not Afghan. Iranian IRGC (Islamic Revolutionary Guard Corps) personnel, also veterans of Syrian service and often the same men who trained and led the Afghan mercs in Syria, are back with their Afghan Shia fighters once more fighting Sunni Islamic terrorists.