Support among Iraqi people for British troops will decline as the foreign force begins to withdraw, a senior soldier says.
Almost 9,000 British troops are stationed in Iraq
Lt Col James Hopkinson said that as Iraqis take greater control of their country "it becomes more and more difficult for ourselves to be here".
"You almost move from being part of the solution to becoming part of the problem," he added.
He made his comments in BBC Radio 4 documentary Desert Rats' Diary.
The UK has about 8,900 personnel stationed in Iraq, mainly in the south east.
Defence Secretary John Reid has signalled that they will start to withdraw and said that Iraqis wanted troops to leave "just as soon as the conditions are right".
Lt Col Hopkinson, commanding officer of the 1st Battalion The Highlanders and commander of the Basra City Battle Group, said persuading Iraqis to take control would be difficult.
"I think it will become particularly difficult as we begin to try to disengage and persuade the Iraqis that they are now in a position (where) they have their own destiny in their own hands.
"It becomes more and more difficult for ourselves to be here. You almost move from being part of the solution to becoming part of the problem. "That's an issue of consent with the people and, I suspect, that will decline as we've got less to give them," he said.
"As we seek to disengage of course, we won't want to put as many resources into these other streams, such as governance, economic development and the like.
"So consent will drop away," Lt Col Hopkinson said.
Desert Rats' Diary will be broadcast on BBC Radio 4 at 2000 GMT on Thursday, 9 February.