By Matthew Davis
BBC News, Washington
The parents of fallen soldiers speak with tremendous moral authority in the eyes of Americans - and in recent weeks their views have become a high-profile part of the debate on the war in Iraq.
Military families have a unique perspective on the war
The protest of one mother, Cindy Sheehan, at the gates of President Bush's ranch has galvanised the anti-war movement.
But it has also spurred many families of US troops killed in Iraq to assert that her views are far removed from their own.
Mr Bush has lost no time in turning such support against those calling for a swift end to the US presence in Iraq.
In two speeches this week before military audiences, he has said that America must honour the sacrifice of the more than 1,800 US troops who have died - by completing their mission.
"We owe them something," the president said on Monday. "We will finish the task that they gave their lives for."
Such sentiments strike a chord with those who need to feel their loved ones have not made the ultimate sacrifice for a lost cause.
They also appeal to the families of serving soldiers - and the many ordinary Americans for whom patriotism entails unconditional support for soldiers fighting in their name.
But some are objecting to the way their sacrifice is becoming part of a political argument.
'Bodies on scrap heap'
Ronald Griffin, whose son was killed in Iraq, has contacted numerous other bereaved parents to get a sense of their reaction to all the attention Mrs Sheehan has been getting.
Mr Bush says the US must honour the sacrifice of fallen soldiers
"I grieve with Mrs Sheehan, for all too well I know the full measure of the agony she is forever going to endure. I honor her son for his service and sacrifice," he wrote in a letter to the Wall Street Journal.
"However, I abhor all that she represents and those who would cast her as the symbol for parents of our fallen soldiers."
He added: "Although we all walk the same sad road of sorrow and agony, we walk it as individuals with all the refreshing uniqueness of our own thoughts shaped in large measure by the life and death of our own fallen hero."
But Mrs Sheehan's is not the only voice crying out against the war.
Paul Schroeder and Rosemary Palmer decided to speak publicly about their grief and anger after their son was one of 20 marines from the same area of Ohio killed in Iraq.
"President Bush had said he wants to support the 1,800 [troops] who've died by continuing the war until we win," Rosemary Palmer told the BBC.
"Well, continuing the same thing without changing what you're doing is like the classic definition of insanity - doing the same thing over and over again and expecting a different result.
"So if we're not going to do it differently, it's just going to be throwing 1,800 more bodies on the same scrap heap."
Such high-profile appeals for a change in policy appear to be having an effect.
Opinion polls suggest more than 50% of Americans think Iraq is going badly and that most also believe some or all US troops should be withdrawn from Iraq.
No one wants young men and women to die simply because others have already done so.
But there are many among the families of the fallen who are convinced by President Bush's arguments for completing the mission in Iraq.
Rhonda Winfield, a Virginia woman whose son Jason was killed in January, said he "went fighting to continue our freedom, and so that his brothers wouldn't have to live in fear of getting on a school bus or going downtown or being in school.
"But when he got there he found... a whole different reason to fight.
"When he saw the way... the local Iraqi women were treated, it just broke his heart and they had such an impact in the short time that he was there - just on how those sort of things changed."
Military families - especially the bereaved - have a deep emotional connection with the war and a unique perspective via the conversations, letters and emails with loved ones engaged in the fighting.
In recent weeks their influence and the moral authority with which they speak have been in sharp focus.
Yet it is clear that while some voices are louder than others, each is as unique as the contribution of their own "fallen hero".