U.S. troops and their allies have another enemy on the Afghan battlefield, one they can't even see, never mind fight.
Iran is sending millions of dollars into the country to promote anti-U.S. sentiment. The money goes into the hands of the Umar Daudzai, chief of staff to President Hamid Karzai.
CBSNews.com Special Report: Afghanistan
CBS News correspondent Allen Pizzey reports that the cash reportedly gives Iranian ambassador Feda Hussein Maliki preferential access to Karzai's inner circle, an Iranian channel to poison relations with Washington.
"The Unites States and its NATO allies will be unable to stop any real, serious Iranian efforts to influence things in Afghanistan," says CBS News Afghanistan consultant Jere van Dyk.
The money won't necessarily buy Iran control, however. Karzai is on good terms with the Iranians. But he would find it difficult if not impossible to stay in power without U.S. backing.
So the Iranians are playing both sides of the battlefront, U.S. sources say, funding, training and supplying intelligence to some elements of the Taliban.
And just to underscore that Tehran can't be left out of the efforts to end the Afghan war, Iranian diplomats were included in high level talks held recently in Rome last week.
"We recognize that Iran has a role to play in the peaceful settlement of the situation in Afghanistan," says U.S. Special Envoy to Afghanistan Richard Holbrooke.
Iranian president Mahmoud Ahmadinejad seems to see that role in less than diplomatic terms. During a visit to Lebanon he said the best exit from Afghanistan for what he called "the occupiers" was to apologize and pay compensation. Presumably that would be different from bags of cash.