It was probably chilly that December day in Fallujah back in 2004. A man you probably never heard of, Lance Corporal Franklin Sweger — along with thousands of Marines and soldiers — was engaged in some of the worst combat since Vietnam.

"Everything’s OK mom, don’t worry about me," he told his mother two weeks before. "I think I’m going to make it."

In less than ten days, the city would be for the most part, secure. Its residents would need years to rebuild after the destruction, and its children would see an astronomical rise in birth defects and other abnormalities.

But for Sweger, Dec. 16 would be the last day to fight. "He was the one who was kicking in the doors and going in first," his father Frank Sweger told MySanAntonio.

Along with his infantry platoon from 1st Battalion 3rd Marines, he was going house-to-house, kicking in doors as he had likely done since the battle had started on Nov. 7. But as he entered one room, friends told me later, he was shot and killed by an insurgent lying in wait.

He was on his last deployment and would've gone on to college. He was funny, a good person, and just 24 years old. Why did he die?

***

The battle that took the life of Lance Corporal Franklin Sweger was the second assault that year on the then-lawless city of Fallujah. Called Operation Phantom Fury (Operation Al Fajr in Arabic, or The Dawn), it was a full-scale attack on a city teeming with insurgents who had months to prepare defenses, booby traps, and explosives throughout the city.

When it was all over, American and friendly forces suffered more than 100 killed and more than 600 wounded. The Red Cross estimated 800 Iraqi civilian deaths. Insurgent deaths were much greater than both but impossible to count.

Why did they die?

***

Lance Cpl. Franklin Sweger US Marine Corps The invasion of Iraq was predicated on the notion of ridding the Hussein regime of "weapons of mass destruction" of course. But in 2004, the game was changed to counterinsurgency — ridding the world of "the terrorists."

And we sure were successful. Until the U.S. pulled out, American soldiers and Marines certainly killed their fair share of terrorists, insurgents, bad guys, and the like. They in turn, killed plenty of us.

Yet for all the blood spilled — of 4,488 military men and women to be precise — there's no good reason why.

The proof of how pointless the entire endeavour was — if you even needed more — came Friday morning, with a report from Liz Sly in the Washington Post.

"At the moment, there is no presence of the Iraqi state in Fallujah," a local journalist who asked not to be named because he fears for his safety told Sly. “The police and the army have abandoned the city, al-Qaeda has taken down all the Iraqi flags and burned them, and it has raised its own flag on all the buildings.”

Fallujah has fallen, and the same scenario is about to happen in the even-larger city of Ramadi.

It shouldn't be such a surprise the place my friends fought for is falling back into civil war. I shouldn't be surprised when the same thing happens in Afghanistan. But it still is, because I don't want it to happen.

Now looking back on his "Last Letter" written Mar. 18, 2013, Tomas Young, a veteran of Iraq who was shot and paralyzed just five days into his deployment, predicted this moment:

"The Iraq War is the largest strategic blunder in U.S. history," he wrote. "It obliterated the balance of power in the Middle East. It installed a corrupt and brutal pro-Iranian government in Baghdad, one cemented in power through the use of torture, death squads and terror. And it has left Iran as the dominant force in the region. On every level—moral, strategic, military and economic—Iraq was a failure."

I'll never know why they died. It wasn't to stop the "mushroom cloud" or to defend the nation after 9/11. It sure wasn't for freedom, democracy, apple pie, or mom and dad back home.

The only reason they died was for the man or woman beside them. They died for their friends.

I'm just not satisfied with that.