KABUL: It was once President Barack Obama's "war of necessity." Now, it's America's forgotten war.

The Afghan conflict generates barely a whisper on the US presidential campaign trail. It's not a hot topic at the office water cooler or in the halls of Congress — even though more than 80,000 American troops are still fighting here and dying at a rate of one a day.

Americans show more interest in the economy and taxes than the latest suicide bombings in a different, distant land. They're more tuned in to the political ad war playing out on television than the deadly fight still raging against the Taliban. Earlier this month, protesters at the Iowa State Fair chanted "Stop the war!" They were referring to one purportedly being waged against the middle class.

By the time voters go to the polls Nov. 6 to choose between Obama and presumptive Republican nominee Mitt Romney, the war will be in its 12th year. For most Americans, that's long enough.

Public opinion remains largely negative toward the war, with 66 per cent opposed to it and just 27 per cent in favour in a May AP-GfK poll.

More recently, a Quinnipiac University poll found that 60 per cent of registered voters felt the US should no longer be involved in Afghanistan. Just 31 per cent said the US is doing the right thing by fighting there now.

Not since the Korean War of the early 1950s — a much shorter but more intense fight — has an armed conflict involving America's sons and daughters captured so little public attention.

"We're bored with it," said Matthew Farwell, who served in the US Army for five years including 16 months in eastern Afghanistan, where he sometimes received letters from grade school students addressed to the brave Marines in Iraq — the wrong war.

"We all laugh about how no one really cares," he said. "All the 'support the troops' stuff is bumper sticker deep."

Farwell, 29, who is now studying at the University of Virginia, said the war is rarely a topic of conversation on campus — and he isn't surprised that it's not discussed much on the campaign trail.

"No one understands how to extricate ourselves from the mess we have made there," he said. "So from a purely political point of view, I wouldn't be talking about it if I were Barack Obama or Mitt Romney either."

Ignoring the Afghan war, though, doesn't make it go away.

More than 1,950 Americans have died in Afghanistan and thousands more have been wounded since President George W. Bush launched attacks on Oct 7, 2001 to rout Al Qaeda.

The war drags on even though Al Qaeda has been largely driven out of Afghanistan and its leader Osama bin Laden is dead.

Strangely, Afghanistan never seemed to grab the same degree of public and media attention as the war in Iraq, which Obama opposed as a "war of choice."

Unlike Iraq, victory in Afghanistan seemed to come quickly. Kabul fell within weeks of the US invasion in October 2001. The hardline Taliban regime was toppled with few US casualties.

But the Bush administration's shift toward war with Iraq left the Western powers without enough resources on the ground, so by 2006 the Taliban had regrouped into a serious military threat.

Candidate Obama promised to refocus America's resources on Afghanistan. But by the time President Obama sent 33,000 more troops to Afghanistan in December 2009, years of war in Iraq and Afghanistan had drained Western resources.

And over time, his administration has grown weary of trying to tackle Afghanistan's seemingly intractable problems of poverty and corruption. The American people have grown weary too.

While most Americans are sympathetic to the plight of the Afghan people, they have become deeply sceptical of President Hamid Karzai's willingness to tackle corruption and political patronage and the coalition's chances of "budging a medieval society" into the modern world, says Ann Marlowe, a visiting fellow at the Hudson Institute, a policy research organisation in Washington.

"With millions of veterans home and talking with their families and friends...some knowledge of just how hard this is has percolated down," said Marlowe, who has travelled to Afghanistan many times.

It has also been hard to show progress on the battlefield.

World War II had its Normandy, Vietnam its Tet Offensive and Iraq its Battle of Fallujah. Afghanistan is a grinding slough in villages and remote valleys where success is measured in increments.

The Afghan war transformed into a series of small, often vicious and intense fights scattered across a country almost as large as Texas.

In July, 40 US service members died in Afghanistan in the deadliest month for American troops so far this year. At least 31 have been killed this month — seven when a helicopter crashed during a firefight with insurgents in what was one of the deadliest air disasters of the war. Ten others were gunned down in attacks from members of the Afghan security forces — either disgruntled turncoats or Taliban infiltrators.

Many argue that Osama’s death justifies a quick US exit from Afghanistan. Others say it's important to stay longer to shore up the Afghan security forces and help build the government so that it can stand on its own. An unstable Afghanistan could again offer sanctuary to militants like Al Qaeda who want to harm American and its allies, they say.

"Those of us who have been at this for a long time continue to think that it's important, and that we have a chance now of a path forward with a long-term perspective that will produce the results," said James Cunningham, the new US ambassador to Afghanistan.

The US-led coalition's combat mission will wind down in the next few years, leading up to the end of 2014 when most international troops will have left or moved into support roles.

Military analysts say the US envisions a post-2014 force of perhaps 20,000 to hunt who it deems as terrorists, train the Afghan forces and keep an eye on neighboring Iran and other regional powerhouse nations.

Americans aren't likely to know the number until later this year. But will anyone other than families of service personnel take note?

"I have heard others say that the danger that their spouses or children are serving in is just simply not being cared about," said Fred Wellman, a 22-year Army veteran who did three tours in Iraq. "I think a lot of veterans feel it is just forgotten."

Political satirist Garry Trudeau captured the apathy about the war in a comic strip this year showing a US servicewoman stationed in Afghanistan calling her brother back home.

After he complains that his children have the flu and how he's struggling to keep up with their hectic hockey schedule, he asks her where she's calling from. She tells him she's in Afghanistan.

"Oh, right, right..." her brother replies. "Wait, we're still there?"