TEHRAN -- They do the jobs that few Iranians would consider. For $11 a day, the Afghans mend shoes, haul bricks, dig drainage channels, push giant wheelbarrows of scavenged debris through treacherous ribbons of cars.
It has been this way since the various wars in Afghanistan sent an estimated 2 million refugees flooding into neighboring Iran. Since April, however, more than 160,000 Afghans have been rounded up and sent home.
Iran plans to expel up to 1 million in what it asserts is an effort to cut down on illegal immigrants and open up new jobs for Iranians.
But Afghanistan warns that the exodus could jeopardize its fragile new stability, and for the United States and others, the move by Tehran offers an unsettling hint of Iranian mischief-making in the region.
One of the givens of the Middle East's diplomacy is Shi'ite Iran's enduring hostility toward the Taliban, the radical Sunni movement whose fall from power in 2001 was welcomed in Tehran.
Yet the growing international pressure aimed at Iran's nuclear program appears to have prompted a complex new strategy for Iran in Afghanistan, suggest Iranian analysts here.
Iran still supports the government of Afghan President Hamid Karzai, they say, but the Islamic Republic is also not averse to asserting itself in a conflict that Washington once thought was over.
"It is better for Iran if America is entangled in Afghanistan with the Taliban," said Abulfazl Amooei, a political analyst for Hamshahri diplomatic magazine, which reflects the views of Iran's Islamist hard-liners.
"Because as soon as the United States has no problem in Afghanistan, it can turn to the next area in the Middle East. It can come to Iran and say, `I am in your neighborhood, and I will attack you if you do not suspend your nuclear enrichment activities.' "
Iran appears to be mounting a high-profile publicity campaign against the United States along its western edge, in Iraq and neighboring Sunni nations in the Persian Gulf, and a subtle, below-the-radar exercise in keeping its options open to the east, in Afghanistan.
For years, Iran's power in the Middle East was held in check through a combination of US sanctions and a long war in the 1980s with Saddam Hussein's Iraq, whose regime was fueled with aid from the United States and Sunni Arab nations that feared the growing influence of the Islamic Republic and the potential expansion of its hard-line theological revolution.
But the US-led military ouster of Hussein in Iraq and the Taliban in Afghanistan during the Bush administration opened a new chapter for Tehran.
Now, President Mahmoud Ahmadinejad of Iran has forged cordial relationships with Iraq's new Shi'ite-dominated government and with Karzai. Last week, the Afghan president rebuffed President Bush's attempts to characterize Iran as a destabilizing force in the region, contending on CNN that Iran had been "a helper" on fighting terrorism and narcotics.
Just as worrisome for Sunni Arab governments in the Middle East, Ahmadinejad's tough talk against the United States and Israel has won Iran unexpected and growing popularity in the Sunni Muslim world.
Tehran now sees itself poised to become the dominant power broker in the Mideast and deeper into Asia.
The Bush administration has charged that Iran is supplying weapons to anti-American fighters in Iraq.
And, recently, US and British officials for the first time said they have intercepted Iranian-made weapons in Afghanistan bound for the Taliban.
The Iranian government vehemently has denied any connection, and the Afghan government also has expressed doubts.
But if such shipments eventually are traced to the Iranian government, this would represent a troublesome new development for the United States and others.