FOR the last 15 years, Iran has hosted more refugees than any other country in the world, according to United Nations. The largest group were Afghans, 3 million of whom fled the 1979 Soviet invasion of their country and the subsequent Soviet-backed Communist government in Kabul.
Since the Communists fell in 1992, Iran has been encouraging the Afghan refugees to leave. Now, three years later, the government's patience is wearing thin. ''When you have guests to stay, there comes a time when you have to ask them to leave,'' says Alaeddin Boroujerdi, Iran's deputy foreign minister.
Tehran's new-found determination is fueled primarily by economics. Inflation is running at over 50 percent, hard currency is scarce, and the country has yet to emerge from its debt crisis.
Since 1979, the refugees have enjoyed free education, medical care, unlimited access to subsidized food, and the right to work in certain sectors and live almost anywhere.
''The Afghans really lived with us,'' says Foroohar Khosravi, an Iranian businessman here. ''They were free to live and work almost anywhere. We didn't keep them in camps like Pakistan.''
Officials from the United Nations High Commission for Refugees (UNHCR) say the cost of supporting Iran's refugee population has been borne almost entirely by the government alone. ''Money is just not coming to Iran,'' says Pierre Bertrand, of the UNHCR office in Tehran. ''The international community is not adequately helping Iran.''
Foreign donors give only $12 million a year to the UN's refugee programs in Iran. Many here feel aggrieved that neighboring Pakistan, which also hosted 3 million Afghans, received up to five times as much money each year. ''Pakistan and Iran divided the refugees ... but Pakistan got all the money and all the credit,'' complains a newspaper editor.
Iranians are fond of complaining about the Afghans. They routinely blame them for rising crime and a thriving cross-border drug trade, which has in turn spread drug use among Iran's youth. Moreover, they accuse the Afghans of taking Iranian jobs, a sensitive point in a country with almost 20 percent unemployment.
Under growing domestic pressure, Tehran has already forced more than 1 million Afghans to return. But repatriating the rest will not be so easy, UN officials warn. Many have sought to evade deportation by disappearing into a semi-legal world of informal employment. Recently, police squads have taken to raiding street markets and construction sites in search of illegal Afghans. Those without papers are detained; many are summarily repatriated.
What irks Iranians even more is that few Afghans express gratitude to their hosts. Most are concerned simply to stay. ''I'm afraid to go to work some days,'' says Zahid Bashir, an Afghan who works as a tailor. ''The police are always watching for us.''
UN officials appreciate the irony of the Afghans' desperation to stay in a country that Iranians are often only too happy to leave. ''Whatever we think of Iran in the West, this country is heaven compared to Afghanistan,'' says Sudang Kaentrakool, a UNHCR official.
But the UNHCR is in a tough position. Officials say they are assisting with repatriation in the hope that the returning Afghans can play a part in restoring peace to their country. But they are also responsible for the refugees' safe return; factional fighting still continues to take hundreds of lives each month in Afghanistan. So while UNHCR staff on the border hand out sackfuls of wheat and $25 a head to returning refugees, senior UN officials spend much of their time persuading the Iranian government to have patience.
With the onset of winter, the refugees have a few months' respite. But the UNHCR expects that it will be more difficult to urge Tehran's restraint next year. ''Iran would like to see many more refugees leave here next year,'' Mr. Kaentrakool says. But even UN officials are sympathetic with the Iranian view. ''The government says it has hosted these people long enough and, in a way, they're right. Fifteen years is a long time,'' Kaentrakool says.