RODRIGUEZ LIVE FIRE COMPLEX, South Korea (April 19, 2012) -- "Don't fire until you see the whites of their eyes."

This probably apocryphal quote applies to modern combat about as much as ramrods, steel pikes and cavalry charges.

To mortar men, purveyors of indirect fire from concealed locations, the idea sounds ludicrous.

Soldiers from 1st Battalion, 21st Infantry Regiment, 2nd Brigade Combat Team, 25th Infantry Division, from Schofield Barracks in Hawaii, participated in mortar training at Rodriguez Live Fire Complex here, April 13, as part of Foal Eagle 2012.

With the air full of cries of "hang it," "fire!" and the incredibly loud sounds of 120 millimeter mortars leaving their tubes at more than 200 meters per second, the "Gimlets" exulted in the training.

"We don't get to train that much on [mortar] drills back in Hawaii, because of the land that we have," said Spc. Jonathan Joubert, a radio transmitter operator for 1-21 Infantry. "Being in Korea, it's pretty nice training. We get to shoot a lot of rounds, and we get the new guys who have just come to the unit trained with our battle drills."

The role of mortars in modern combat is quite simple according to 1st Lt. Scott Guo, mortar platoon leader for 1-21 Infantry.

"These systems are the infantry platoon and company's most reactive, in terms of indirect fire support because they're directly tied to the battalion commander. It only requires him to authorize those fires," Guo said.

Guo said it's the simplicity of the command and control that makes mortar such a formidable weapon, "If you want close air support or close combat aviation, [the battalion commander] needs to coordinate with different levels of the Army hierarchy, but with indirect fires from these mortars, all he has to say is, 'hey mortars, make it happen,' and we make it happen."

As with many weapons systems, there are unseen components that are just as important as the highly visible parts. For mortars, that unseen component is the forward observer.

"For our mortar systems, while we can shoot at an enemy that we can see, we call that 'direct lay method,' one of the most powerful ways that we can destroy the enemy is to shoot at them from a hidden area where there's no direct line of sight," Guo said, "The forward observer provides us eyes and ears; he gives us the location of the enemy, and based on that, we fire rounds onto the target. After we destroy the enemy, [the forward observer] gives us a description of what the mission accomplished."

The forward observers working with 1-21 Infantry's mortars were staged overlooking the target area from Manchu Hill.

"In a real-world situation, this makes perfect tactical sense," Guo said, "The mortars are hidden away, ready to engage at a moment's notice in a firing point, and the forward observers are closer to the suspected enemy locations."

Guo said the opportunity to train new mortar Soldiers, both the teams launching projectiles and the all-important forward observers, was a huge benefit of the wide expanse of terrain available to him.

"Any chance we have to train with the forward observers is great," said Guo, "Their mission is to call in fires and adjust fires as accurately as possible, our mission is to provide those fires."

Foal Eagle maintains the readiness of the ROK-U.S. Combined Forces Command to deter or defeat aggression against South Korea and to maintain stability in Northeast Asia.

Occurring around the same time every year, this year Foal Eagle runs from March 1 to April 30. The field training exercise is defensive in nature.