Maryland National Guard Sgt. Darren Lebowitz is leaving soon for Afghanistan as many U.S. troops return home.
Lebowitz, who has served three tours in Iraq, volunteered for the mission.
"I'm a glutton for punishment," he said as he trained Tuesday at this National Guard installation in Central Pennsylvania.
As the United States and its coalition partners draw forces out of Afghanistan, more than 250 Maryland guardsmen are heading in. Members of three military police units are preparing for deployments to Kandahar and Bagram, where they will work with Afghan forces, provide security and take on any other assignments that might arise.
"We're all aware of the emerging missions and changing missions in Afghanistan," said Maj. Gen. James A. Adkins, commander of the Maryland National Guard. "We teach our soldiers to be flexible. I think our mission has changed a couple of times in Afghanistan so far, and I expect it to change again."
With NATO combat forces scheduled to withdraw by the end of 2014, commanders have stepped up efforts to train the Afghan National Security Forces.
Meanwhile, a rise in attacks on NATO members by Afghan security personnel or by attackers wearing their uniform is straining relations. Five such attacks in the past 10 days have left seven Americans dead.
"It's obviously very troubling, not just to us, but it's also very troubling to our Afghan partners," U.S. Ambassador James Cunningham told reporters Monday in the capital, Kabul. "There's a lot of work being done to understand why this is happening."
Thirty-four coalition troops have been killed this year by Afghan forces or by attackers posing as them. The victims include Maryland National Guard Maj. Robert J. Marchanti II of Baltimore County, who was shot in February inside a supposedly secure Afghan ministry building in Kabul.
In October, the Maryland Guard's 115th Military Police Battalion, based in Salisbury, is sending 73 soldiers to Kandahar, where their work will include mentoring the Afghan National Police.
The 290th Military Police Company, based in Parkville, will send 92 soldiers to Bagram Airbase in Eastern Afghanistan in February. They are to be joined a month later by 92 soldiers from the 200th Military Police Company, based in Catonsville.
Adkins said their mission may include providing security for key leaders, holding and transporting detainees, and other tasks.
"Any time you go into an environment where we are reducing the number of forces, we've got to be flexible enough to fill in any needs that may arise," he said. "After 10 years of war, we know that we have sent units in prepared to do one mission and then they may be pointed in another direction. We just have to be flexible enough to do that."
The Maryland National Guard now has 146 soldiers in Afghanistan working in information operations, aviation support and special forces. More than 3,600 Maryland Guardsmen have served in the country since Sept. 11, 2001.
On Tuesday, Maryland soldiers were at Fort Indiantown Gap, where they have been familiarizing themselves since last week with their new M1117 Guardian armored security vehicles. The guardsmen have taken delivery of eight of the 48 they are to receive.
The 16-ton vehicles carry a .50-caliber Browning machine gun and a 40 mm Mark 19 grenade launcher. The guardsmen fired the weapons for the first time Tuesday, blasting targets on the range and sending echoes through the wooded valley.
"I love shooting," said Pvt. Katie Collins after climbing from the turret of her vehicle. She described the Guardian as smoother handling and roomier than the Humvee it replaces.
The Guardian also is considered safer. In a Humvee, the gunner sits half-exposed through a hole in the roof; in a Guardian, the gunner sits inside.
The Army sought armored vehicles for urban operations after the Battle of Mogadishu in 1993, when U.S. forces fought to rescue crew members from two Black Hawk helicopters downed in Somalia's capital. It began purchasing Guardian armored security vehicles for military police units in 1999.
"You can do just about anything with it," said Lt. Andrew Lyerly. "It's excellent for scout operations. You can do patrolling with it. It's a fast system. ... There's not a whole lot it can't do in the urban environment."
The Associated Press contributed to this article.