WASHINGTON, Sept. 17 (Xinhua) -- Twenty years on, the U.S. "war on terror" seems to be losing steam. The U.S. military's recent humiliating retreat from Afghanistan reminded the world of the futility and catastrophic impact of U.S. post-9/11 wars.
To veterans who fought these wars, the Afghanistan withdrawal debacle, combined with the 20th anniversary of 9/11, brought back traumatic memories of killings and destruction, triggering a wave of reflection and remorse. WORTH IT OR NOT
After 20 years of fighting the "war on terror," U.S. veterans are still struggling to address the legacy of 9/11.
As America's longest war ended with the Afghanistan withdrawal, many U.S. veterans are now haunted by the question of whether their sacrifice amounted to anything.
Na'ilah Amaru, 39, is an army veteran enlisted when she was 18 and served for four years, including one combat tour in Iraq.
"I was 21 when I was in Iraq, fighting for democracy, liberation and trying to bring all the ideals of America into a new country ... Still, after all this time, we have not fully realized those ideals here at home," Amaru said.
"American soldiers lost their lives, and I never want to say their sacrifice wasn't worth it," Amaru said in an interview with the 19th News. "But as someone who has been on the ground and watched from afar for the last 17 years, we have to be honest about how we've failed, what we could and should have done better for our soldiers returning home, for the soldiers who didn't make it back and our allies who stood beside us for 20 years," she added.
"Fragile or failed states are hotbeds for terrorism, and I do think that we have created new hotbeds as a result of that," Tracy Walder, a former officer with the CIA Counterterrorism Center told CNBC.
Another veteran, Julie, is an active-duty member of the Air Force who joined the military after the 9/11 attacks. "As we approach the 20-year point, I'm wondering what my life would look like if I hadn't joined," Julie told the 19th News. "I wonder if my spirit of service was wasted. I wonder if the lives of people I know who killed themselves after serving were wasted."
Views among veterans on U.S. military engagement in Iraq and Afghanistan are more negative than positive.
According to a Pew Research Center survey of veterans, a majority of U.S. military veterans say the wars in Iraq and Afghanistan were not worth fighting. The survey shows that veterans who served in either Iraq or Afghanistan are no more supportive of those engagements than those who did not serve in these wars. And views do not differ based on rank or combat experience. HIGH HUMAN, ECONOMIC COST
In the 20-year post-9/11 wars, millions of lives have been lost and trillions of U.S. dollars spent.
Dustin Simmons was 23 when he enlisted in the army. He served from 2006 to 2016 and lost several friends in the two decades of war.
"I've lost a lot of buddies just because they couldn't handle the stuff in the military," Simmons told The Oklahoman newspaper. "They've committed suicide ... This is almost a nail in the coffin. A lot of the veterans feel like it's all for nothing."
Various surveys show that suicide rates among active military personnel and veterans of the post-9/11 wars are reaching new peaks.
Since 2001, about 1.9 to 3 million service members have served in post-9/11 war operations in Afghanistan and Iraq, and over half of them have deployed more than once, according to a report of the Costs of War project at Brown University.
An estimated 30,177 active-duty personnel and war veterans of post-9/11 have died of suicide, more than four times the number of those killed in post-9/11 war operations, which stood at 7,057, said the report.
Besides, America's two-decade long "war on terror" has cost itself at least 8 trillion dollars and resulted in over 929,000 deaths, including more than 387,000 civilians, the report said. LESSONS LEARNED
On the 20th anniversary of 9/11 this year, some U.S. veterans and ex-CIA members shared their personal reflections to CNBC on lessons America has learned and failed to learn since 9/11.
"Honestly, I don't think we've learned that much; I think we're probably destined to be making some of those mistakes again," Nada Bakos, a former CIA analyst, said. "But hopefully we're done with giant occupations of other countries."
"I hope that we have gotten to the point now where we understand that we can't spread our democracy and rebuild other countries in our model, in a way that we were naive enough to think would work at that time," Bakos added.
"I think many Americans have learned not to trust their government. 'Leadership' lied to the American public for 20 years, while the actual situation on the ground in Afghanistan was no mystery to the people who served there," said Jay, a former U.S. Marine and Afghanistan war veteran.
"This has gone on for two decades as senior 'leadership' moves from the military or government into high-paying defense contractor jobs," he added.
The 9/11 attacks changed the trajectory of a generation of people, with millions of U.S. servicemen involved in post-9/11 wars.