A British officer killed in Iraq felt troops were "making a difference, little by little", his father said.
Three others were injured when the device exploded on a road
Brigadier John Palmer said the vast majority of Iraqis were better off because of people like his son, Lieutenant Richard Palmer, 27.
The Royal Scots Dragoon Guards soldier, from Ware, Hertfordshire, was the 104th UK military fatality of the conflict.
He died on Saturday when his patrol vehicle was caught in an explosion near Ad Dayr, north-west of Basra.
Brig Palmer said his son had no doubts about his role. He said: "He still believed that what they were doing, they were doing it very professionally and that they were, little by little, making a difference for the majority of the Iraqi population.
"Clearly there were lots of members of the population who didn't want them there, but the vast majority, they were better off because people like Richard were there."
He said his son was aware of the risks in Iraq: "He knew how dangerous it was out there and he was doing a job that he wanted to do and was worthwhile.
"That's a worthwhile memory, that if he had to go, he went doing something that he really believed in."
He said he had the qualities of an excellent officer: "I can't ever imagine him being unfair, I can't ever imagine him doing something because it would benefit him rather than anybody else
"I'm sorry, it's probably just rose-tinted glasses, but we think the world of him."
He described his son as "a much loved son, grandson, brother, uncle and boyfriend, with a huge number of very good friends".
"He was enormously proud to be a soldier and in particular to be a member of the Royal Scots Dragoon Guards," he said.
'Intelligent and charming'
Lt Palmer's commanding officer said the regiment had lost a "great ambassador, a splendid soldier and a fine friend".
The officer was "an intelligent, charming, talented yet incredibly modest individual", said Lieutenant Colonel Ben Edwards.
"Despite having only served with the regiment for just under two years, he was widely regarded by soldier and officer alike as a star of the future," he said.
"Individuals such as Richard have made a tangible difference to the future of the people of Iraq.
"On a daily basis they put their lives at risk as they endeavour to improve the security situation within the country."
Three of his colleagues were slightly injured in the attack.
The soldiers were taking part in a joint patrol with the Iraqi Army at the time.
The death comes after a suicide bomb attack on Friday close to the British logistics base at Shaibah, near Basra, in which four soldiers suffered minor injuries.
The last British soldiers to die in Iraq were Captain Richard Holmes and Private Lee Ellis, both from 2nd Battalion The Parachute Regiment and attached to the Royal Scots Dragoon Guards.
They were part of a routine patrol that was targeted by a roadside bomb on the outskirts of Amara, southern Iraq, on 28 February.
Defence Secretary John Reid announced last month that the number of UK troops in Iraq would be reduced by 800 to 7,000.