A Soldier gently pulls a drawer open with a hook. The Soldier, fully adorned in nuclear, biological and chemical protective gear, checks every item in the room, calling out "Marco," so Soldiers outside could respond with "Polo," ensuring the individual inside is still safe and conscious.

After the whole room is checked for explosive devices, a second Soldier enters - documents and samples equipment for evidence of chemical and biological agents.

The Soldiers are meticulous, checking everything in the room. They have to be sure every possible chemical or biological agent is documented. There is no room for mistakes in this mission.

This is part what Soldiers from the 23rd Chemical, Biological, Radiological, Nuclear and Explosive, or CBRNE, Ordnance Battalion, 1st Armored Brigade Combat Team, 2nd Infantry Division, trained on during their month-long field training exercise, March 15 to April 14.

Staff Sgt. Rolando Contreras, a sample team leader in the 501st Chemical, Biological, Radiological, Nuclear, Radiological Technical Escort Company, or CBRNE TE, 23rd CBRNE, said this type of hands-on, high-stress training is exactly what it takes to stay prepared for the CBRNE mission on the Korean Peninsula.

Working in realistic environments forced the Soldiers to refine how they used Korean Augmentation to the U.S. Army, or KATUSA, Soldiers for support. The KATUSAs allowed the teams to quickly identify potential hazards.

"One of the things that did go well was using KATUSA support on analytics on being able to read the Hangeul anywhere allowing us to get as much information as fast as possible," said Staff Sgt. Lucas Michael Applewhite, an explosive ordnance disposal team leader in the 501st CBRNE TE Company, 23rd CBRNE.

The training also helped the alliance by building bonds and reinforcing tactics, techniques and procedures by working alongside the Republic of Korea, or ROK, Army, 24th Chemical, Biological, Radiological, or CBR, Special Task Battalion. Soldiers in the units worked at different locations in South Korea to include Camp Stanley, the South Korean Armed Forces CBR Defense Command and Rodriguez Live Fire Complex.

"When we do combined trainings with the U.S. counterparts, we usually do it at Rodriguez Live Fire Range, Warrior Camp, and for this time, we invited U.S. Soldiers to newly constructed CBR training facilities at the [South Korean] Armed Force CBR Defense Command," said ROK0 Navy Chief Petty Officer You Hyeon-min, chemical operations non-commissioned officer in Company 3, 24th CBR Special Task Battalion. "We conduct the training together to compare differences in both nations' doctrines; thus, our goal is to establish one procedure for the process, so that we can apply it on our army, navy and air force."

The training allowed both sides to hone their skills and learn from each other.

"[The ROK and U.S. Soldiers] will be looking at what each one of us is doing, basically exchanging tactics, techniques and procedures, and then of course at the same time this gives us the opportunity to see how the ROK works and the ROK to see how we work," said Capt. Philip Kline, team leader in the Chemical Response Team 2, 501st CBRN TE Company, 23rd CBRNE.

Along with company team certifications on CBRNE tasks, the Soldiers qualified on individual weapons, went through medical lanes, received combat lifesaver refreshers and trained on night drivers training