The US military had little difficulty toppling Saddam Hussein's regime in 2003. Yet the post-invasion challenges in Iraq ? promoting democracy, rebuilding infrastructure, providing security, beating back an anti-American insurgency and defusing the Sunni-Shiite conflict ? have tested the limits of the armed forces. As the Iraq war enters its sixth year, VOA's Adam Phillips examines how has it affected officer training at United States Military Academy at West Point, New York.

Almost any civilian would be impressed by the daily lunch formation at West Point, the nation's most elite training college for Army officers. Seemingly endless lines of officer cadets ? dressed in the charcoal gray uniforms that have been traditional at West Point for much of its 206-year history ? march to their oaken dining hall.

But the counter-insurgency war cadets like Andrew Byers are being trained to wage in Iraq differs in crucial ways from conventional wars fought by West Point graduates like Dwight D. Eisenhower, who commanded Allied Forces in World War Two, and Ulysses S. Grant, who led the Union Army during the Civil War.

When Cadet Andrew Byers arrived in 2005, his training involved digging foxholes, rifle skill and land navigation. The next summer, the emphasis was on squad attacks and platoon formations, and then on the construction of forward operating bases, a strategy where groups of soldiers carry their own security with them, rather than relying on fixed positions in a trench or a fort.

But Byers says the most dramatic change in basic field training came about in 2007, when the academy started to bring in expatriates from the Middle East and Iraq. "We were learning how to use translators in our operations and communicating with people in different languages and different scenarios."

He acknowledges that this is a contrast to the "sexier" training activities of his father's generation where "you go in and bring the helicopter down and everybody runs out and you raid the village and you're kicking in doors."

But Byers says even a cursory glance at the television news makes it obvious that this is not the way this war is being fought in places like Iraq and Afghanistan. "You are not trying to alienate the population. You are trying to work with them in order to establish a rule of law."

So now, says Byers, instead of practice raids on West Point's mock village, there is a different scenario. "The company commander goes in first and talks to the village mullah or sheikh," Byers says, "trying to convince them, through the translator, to let the platoon into the village 'because this is what we think is here.'"

Byers says that this so-called "low intensity conflict" isn't what many at West Point would always prefer. "To be completely honest, I think a lot of people here wish they were born in a different decade where war was the simple action of 'friend' and 'enemy' compared to this type of ambiguous warfare that keeps us scratching our heads time and time again."

Ever the since the invention of warfare, it's been a given that when your enemy shoots on you, you fire back. But when the snipers and other unseen enemies in Iraq strike, they often melt back into a civilian population the American army is charged with protecting.

Lieutenant Colonel and West Point history professor Gian Gentile, who has served twice as a battalion commander in Iraq, has learned to respond to such attacks with intelligence-gathering and relationship-building. This requires extraordinary self-control for troops whose every instinct is to strike back at the enemy immediately and hard.

"The challenge for a commander in a counter insurgency is to provide meaning in those gaps," says Gentile, "because the soldier can't see the immediate results of his actions over an extended period of time when all he can remember is that his best friend had his two legs blown off or was shot in the head by a sniper and killed."

Some experts say the fight against al-Qaida is easier now, since many groups that once shielded the terrorists now betray them ? often for American cash. But Lieutenant Colonel Kevin Farrell, who chairs West Point's Military History Division, says his own experience with the motives of America's various enemies in Iraq ? from Mahdi militia members, to disaffected Baathist party members, to organized kidnapping rings to foreign fighters and agents ? has made even the term 'al-Qaida' too broad to be of much use.

"All these groups would actively try to kill Americans, and would often want to kill each other," says Farrell, "and the way these different groups overlapped or cooperated would change over a given period."

While knowledge of Iraq's shifting political landscape is essential, so is being able to protect one's truck convoy from improvised explosive devices or to identify a potential suicide bomber at military checkpoints.

West Point tactics professor Major David Waters teaches cadets to watch out for Iraqis in bulky clothing during warm weather; they may be concealing a bomb. The driver of a car riding low may have bad shock absorbers or perhaps he's got five tons of homemade C-4 [explosive] or fertilizer bombs in his trunk. "It's a thinking man's sport," says Major Waters.

At five years and counting since the invasion of Iraq, the American army is still on a multi-billion dollar learning curve. But it has maintained its storied "can do" attitude. "We've got a mission," says one cadet, "and we say 'yes!' We will figure out a way to get it done."