On Wednesday, the Wall Street Journal reported:

Ghulam Yahya, a former mayor of this ancient city along the Silk Road, battled the Taliban for years and worked hand in hand with Western officials to rebuild the country's industrial hub.

Now, Mr. Yahya is firing rockets at the Herat airport and nearby coalition military headquarters. He has kidnapped soldiers and foreign contractors, claimed the downing of an Afghan army helicopter and planted bombs in central Herat -- including one that killed a district police chief and more than a dozen bystanders last month.

Yahya spent some time living as a refugee in Iran. So it is no surprise where he is getting his weapons from (emphasis added):

Shared hostility to Western presence in Afghanistan cemented Mr. Yahya's alliance with the Pashtun Taliban. In an interview with Qatar's al Jazeera satellite TV network, Mr. Yahya boasted he has hosted Arab jihadis. Mr. Khan, the water and power minister, said Mr. Yahya turned to the Taliban because "everyone naturally needs support."

The insurgent also appears to be getting some help from Iran, which used to cooperate with the West against the Taliban in the past. "The rockets that were launched against us [by Yahya] were Iranian-made," said Brig. Gen. Rosario Castellano, the Herat-based Italian commander of international forces in western Afghanistan. "The Iranians want a stable Afghanistan. But, at the same time, they also don't want Westerners to trample upon Afghan soil."

I think Castellano's take is mostly accurate. I don't think Iran really wants a "stable" Afghanistan in the sense that many others mean. If the Iranian regime really wanted "stability," then it wouldn't be supporting the prime sources of instability. Iran wants a state into which it can project its radical power. To do that, American and Western forces have to be pushed out. Thus, the Iranian regime backs warlords like Yahya who are willing to flip sides, and even the mullahs' one-time enemy - the Taliban. Would Iran possibly turn on the Taliban at some point in the future? Sure, why not?

But, for now, Iran sees the Taliban as a useful ally against the true Great Satan - America.

And we should keep in mind that the Iranians have collaborated with the Taliban against America for a surpisingly long time.