Hundreds of veterans from across the UK have gathered in Lisburn to mark the 50th anniversary of Operation Banner, the British Army’s deployment in Northern Ireland.
Sir Robert Pascoe led Operation Banner from 1985 to 1988, and returned to mark 50 years since the British Army’s longest continuous deployment began.
He addressed a ceremony near Belfast attended by scores of veterans commemorating loss of military lives from 1969 to 2005.
The investigation of soldiers over alleged wrongdoing during the Northern Ireland conflict is "unfair", a former commanding officer said.
Sir Robert said: "We all know that the current process is unfair and we look to our politicians to sort it out without delay."
He noted "exaggerated" stories of detectives holding bias against the army, a perception not borne out by the number of cases investigated.
The former senior officer hoped the appointment of veterans minister Johnny Mercer would create a way out of the “distressing” situation.
Sir Robert added: "Many people have forgotten that troops were first deployed to protect members of the Catholic community in Londonderry, where inter-communal violence in the Bogside could not be contained by the overstretched Royal Ulster Constabulary (RUC).
"Some people remember those early days, when tea and cakes were on offer.
"But the honeymoon period did not last long and we were soon engaged in a seemingly endless and bitter struggle against the IRA and their supporters."
The retired officer added: "It was our job to hold the ring, to limit the attacks by the terrorists and sap their will to continue the fight, this you did."
During a drumhead service, the green blazers of former Royal Irish soldiers lined a sports field along with military standards.
Their berets bore green feathers and on their chests were pinned gleaming medals commemorating sacrifices during service.
Later they paraded through Lisburn town centre, past crowds of cheering wellwishers, preceded by brass bands.
An "emotional and frightened" Christopher Perkin, a former craftsman in the Royal Mechanical Engineers, returned to Northern Ireland for the first time for 30 years.
He said: "It just felt right to come back."
He was based in Londonderry, and within a couple of hours of deployment was in the republican Bogside estate.
He said: "Losing mates was the biggest one, watching people being blown up was probably the worst part."
Yvonne Black, whose husband David was shot dead by dissident republicans in 2012 as he drove to work at Maghaberry high security jail, said it was a difficult, emotional and proud day.
She said: "Our husbands were prison officers and they were never seen out and they were always behind the walls and they were the service that protected without actually being recognised and being seen."
DUP leader Arlene Foster added: "These people who are here today stood between us and anarchy during the 70s, 80s and 90s."