"We haven't seen the real refugee crisis yet," said Joost Hiltermann, Middle East project director for the International Crisis Group.
UNDERCOUNT SUSPECTED
Of the official count of 4.2 million displaced people, more than 2 million have been displaced inside Iraq, while another 1.4 million are believed to be in Syria and as many as 500,000 to 750,000 people in Jordan.
Judith Yaphe, an Iraq expert at the National Defense University in Washington, is among those who suspect the estimates significantly undercount the actual numbers.
"Both on an anecdotal level and on a research level, the real numbers don't match up with the declared numbers," said Yaphe, who believes the number of refugees living outside Iraq could be nearly double the UNHCR estimate.
"There are people who came illegally, or came legally but don't want to declare themselves as refugees ... They feel that if you declare yourself you are labeled: the state can control you; you could be deported; things could be done to you."
Dana Graber Ladek, Iraqi specialist for the International Organization for Migration, said thousands more inside Iraq, including many Sunnis, have chosen not to register with the Shi'ite-dominated government often because of security concerns.
"It's very difficult to know how many those might be. It could be thousands, it could be hundreds of thousands. Who knows? If we talk about those within the country it could be even a million," she said.
But unregistered people in Iraq may not mean a greater strain on the country, because they tend to be better educated and to hold steady jobs.
"It doesn't change the fact that they were forced from their homes. But are they the most vulnerable? No. Probably the 2.25 million who have been assessed or registered are the most vulnerable of the displaced," Ladek said.
