Lt. Col. Chris Hughes had a tough decision to make on a tense street in a southern Iraqi city, so he gave his 130 troops a set of orders that would draw international attention.
Drop to one knee. Point your weapons to the ground. And smile.
His military adversary that day was an angry Iraqi mob that had misinterpreted the troops' intentions.
To avoid a violent confrontation, he ended up marching his troops out of town and returning the next day to a much calmer populace.
To a top U.S. Army scholar on leadership, Colonel Hughes' decision is a symbol of how far the Army has come since Vietnam - just as it faces its toughest counter-insurgency operation since then.
“That kind of savvy behavior doesn't just happen by accident. It's a matter of education and training in a professional force,” said Col. Tom Kolditz, who heads the department of behavioral sciences and leadership at the U.S. Military Academy at West Point.
“And without denigrating the Army we fielded in Vietnam, it was a largely conscript Army - we had the draft in place,” he said. “With a professional volunteer force, you get a different product altogether.”
The demographics alone show a much different fighting force.
The Army's 480,000 troop strength is a third of what it fielded at the height of Vietnam. Fifteen percent of today's soldiers are women, compared to 2 percent at the time of the Vietnam conflict.
But Colonel Kolditz and others say a key change is beyond the numbers: training regarding civilians. That can be traced to the lessons of Vietnam - particularly the 1968 My Lai massacre in which U.S. soldiers killed about 500 civilians.
In the wake of the massacre, a commission headed by Lt. Gen. William Peers issued a scathing report that criticized the unit's leadership and called the amount of training for troops on war crimes “nothing short of ludicrous.”
Three decades ago, soldiers received two hours of instruction during basic training, but retired Army law professor H. Wayne Elliott said the class was viewed as a formality.
Now soldiers - and their commanders - receive training on war crimes throughout their careers.
“I don't think the Army could do much more than it is doing and has been doing for the last 10 to 15 years,” he said.
It's not just classroom instruction.
Tucked into a hilly, wooded section of west-central Louisiana, Fort Polk hosts about 10 mock battles a year for various units armed with laser-shooting guns.
Often the battle plots are similar to the warfare found in Vietnam: U.S. troops helping an allied government fight off guerrilla soldiers and a power-hungry neighbor.
The training is similar in another respect, too: The scenarios include mock civilians - also equipped with laser-sensing devices to know when they've been mistakenly or unfairly shot, said Maj. Ron Elliott, a center spokesman.
“In everything we do here, civilians are a part of the battlefield,” he said.
Conversely, Colonel Kolditz said, the training for fighters in Vietnam was “all tactical. There was never the creativity to inject these kinds of civilian activities into training. But the mission of the Army has changed.”
Beyond fighting the traditional wars, soldiers now are deployed as peacekeepers in unstable countries.
And even the traditional wars can turn into counterinsurgencies - where guerrilla fighters often blend into the population - such as in Iraq.
In the case of Colonel Hughes' 101st Airborne battalion, they were marching into Najaf, Iraq, in April after the major fighting there had ended.
They were hoping to meet with an influential cleric to get his support for their occupation but instead were met by hundreds of chanting residents fearing the Americans were going to arrest the cleric or occupy a nearby Muslim holy site.
Colonel Hughes' decision to walk away - avoiding a potential conflict with civilians - made news across the world.
But with guerrillas in Iraq continuing hit-and-run tactics similar to Vietnam, some fearful U.S. troops have mistakenly targeted civilians.
In one case last month, troops mistakenly killed eight Iraqi policemen who were chasing highway bandits.
While such accidental killings are not the same as the executions of civilians at My Lai or by Tiger Force, it's no time to forget the lessons of either, said Brig. Gen. John H. Johns, who once taught leadership at West Point.
“Particularly in guerrilla warfare,” he said, “when you don't know who the enemy is, it's easy to say, `Kill them all. Kill them all.'”