But there was small solace this week for the Cork native when he learned the New Jersey town where he brought up his son is to rename its post office in his honour.
The 59-year-old is still angry about the causes of the war which cost Matthew and thousands of others their lives.
He also finds it ironic that he told his son it was good that the world was so quiet when he enlisted as an 18-year-old in September 2000, a year before the 9/11 attacks that prompted the US military campaigns first in Afghanistan and then Iraq.
“He was a gunner on a Humvee protecting a convoy when a car driven by a suicide bomber rammed into them and he took a piece of shrapnel to the head,” explains John.
Matthew died on May 5, 2006, nine days after the attack, at Bethesda military hospital in Maryland, where he was flown to after the incident in Fallujah.
“They performed emergency brain surgery in Iraq, his whole frontal lobe was removed, and after other surgery he really had no brain left. They told us they could keep him like that for 20 years but we didn’t want that and he wouldn’t have wanted it,” said John.
“It was a horrific scene in the head injury ward, some of the young men and women were going to be half-paralysed, it was nine days of nightmare scenarios. The only worthwhile thing that came of the whole Iraq war was the removal of Saddam Hussein but there had to be some other way, my son and thousands of others shouldn’t have died to achieve it,” he said.
Having been born in Cork city and moving with his family when he was just two, John returned here in 2008 after difficulty returning to his job as a clerk in the US postal service following Matthew’s death.
John had lobbied his local Congressman to try and have a federal building named after his son, but left the campaign to some of Matthew’s friends when he left New Jersey for Ireland.
“I have an email alert set up to tell me whenever he is mentioned in news articles, and I got a message on Tuesday to tell me President Obama had signed the bill into law,” said John, who lives in Crosshaven.
New Jersey congressman Steve Rothman, who sponsored the bill, said Matthew is a true American hero and the post office will stand as a testament to his bravery and sacrifice.
Following the signing of House of Representatives Bill 789 by Barack Obama, John expects there will be a renaming ceremony of the post office in Little Ferry as Sergeant Matthew J Fenton Post Office in the spring or summer. But he faces a more poignant event much sooner.
“My son would have been 30 on January 17, that will be tough. It’s good that he will be remembered for a long time, every parent who loses a child wants them to be remembered.”
He meets other grieving families at monthly meetings of Anam Cara, the support group for bereaved parents. “They say that time heals and for the first time I think it’s true. If you asked me this time last year, I probably wouldn’t have agreed but although things will never be the same, my head is clearing and there is progress.”