With most foreign combat troops set to withdraw from Afghanistan by 2014, Iran is using the media in the war-ravaged nation to gain influence, a worrying issue for Washington.
Nearly a third of Afghanistan's media is backed by Iran, either financially or through providing content, Afghan officials and media groups say.
"What Iran wants, what they are striving at, is a power base in Afghanistan that can counter American influence," said a senior government official, who like others for this report, spoke on condition of anonymity.
"They are without a doubt doing this through supporting and funding our media."
Iran spends $100-million a year in Afghanistan, much of it on the media, civil-society projects and religious schools, says Davood Moradian, a former Foreign Ministry adviser who now teaches at the American University in Kabul. "It is using Afghanistan to send a message to America that it can't be messed with. Afghanistan becomes a managed battlefield as a result."
Officials in Tehran could not be reached for comment despite repeated attempts and the Iranian embassy in Kabul said it was not prepared to talk about the issues raised in this report.
The latest flashpoint is the recent signing of a long-term strategic agreement between the United States and Afghanistan.
Iran, whose frayed ties with the United States have worsened over its disputed nuclear program, sees the pact as a threat. Iranian-backed media in Afghanistan responded by churning out reports critical of the agreement, and Tehran's ambassador to Afghanistan, Abu Fazel Zohrawand, threatened to expel Iran's one million Afghan refugees if the pact was not rejected.
Afghanistan's intelligence department, the National Directorate of Security, had earlier gone public with Iran's alleged meddling in the media, saying that weekly newspaper Ensaf and TV channels Tamadon and Noor had received financial support from Iran.
As the United States prepares for its own dispirited withdrawal from Afghanistan, it is worried about Iran gaining a strategic advantage in Afghanistan, after seeing Tehran win influence in Iraq following the 2003 U.S. invasion.
More than half of the 171 TV, satellite channels and radio stations licensed to broadcast in Iraq today are funded by Iran, with others backed by the United States and Arabic Gulf countries, government communications officials say.
Iran's media strategy is but one strand in a multi-pronged projection of "soft power" into Afghanistan. The two countries share cultural, language and historical links – for centuries they were part of the ancient Persian empire – as well as a long and porous border.
Iran's vehement opposition to the new strategic pact with the United States appears to have intensified efforts to influence public opinion about it.
Ensaf newspaper, one of the three media outlets the government has said receives funding from Iran, and whose parent company, Avapress, has offices in Tehran, has published six critical articles on the pact since it was signed by President Barack Obama on a whistle-stop visit to Kabul on May 2.
Iran first started attempting to influence Afghan affairs through the media in 2006, said Abdul Mujeeb Khalvatgar, executive director of the Afghan media-development group Nai.
"The pace has been quickening since 2011, which is when Iran began to actually inject its viewpoint into Afghan media," he said.
Kabul is countering with its own pressure.
The Kabul-based reporter of Iran's semi-official Fars News Agency, Abdul Hakimi, was arrested two weeks ago on charges of spying, Afghan officials said. The NDS declined to comment.