A light, peaceful snow draped the West Tisbury School last Friday morning. If principal Michael Halt sees snow again in the coming months, it may be a world away, perhaps from a remote outpost in the central highlands of Afghanistan or the jagged Hindu Kush.

In early February Mr. Halt, who has been called up from the Marine Corps reserves for what will be his second tour of duty in the past three years, will officially mobilize. He doesn’t know with whom he is working or what he is going to be doing. In other words, according to Mr. Halt, “It’s going to be a lot like the first day of school.”

On Friday Mr. Halt’s fellow teachers held an impromptu going-away ceremony in the school cafeteria with a light continental style breakfast buffet. It was a modest affair, but entirely appropriate given how manifestly uncomfortable Mr. Halt is receiving praise of any kind. As his colleagues heaped him with well-wishes and sentiments of gratitude, he struggled to change the subject, deflecting every kind word with an equally gracious one.

“Well, I appreciate that, thank you, and I just want to tell you how much I appreciate the great job you’ve done this year,” he offered with reflexive and genuine modesty to his many grateful colleagues.

The school has been through this before. From January to October of 2007 Mr. Halt served in Iraq with the 30th Naval Construction Regiment, also known as the Seabees, in Camp Fallaujah, Iraq. He kept his pupils apprised of his deployment in a blog posted on the West Tisbury School Web site and was overwhelmed by the welcome he received upon returning.

“When I came back I thought I’d touch base with Dan McCarthy, the interim principal at the time, and let him know I was back and see what I could do to help. And then the whole school just poured out to welcome me. It was pretty amazing.”

For this deployment Mr. Halt will spend the next few weeks in California meeting his fellow soldiers and learning about his mission with the First Marine Expeditionary Force. He expects to ship overseas in early March for a 13-month deployment.

“It’s a different country so everything from the geography to the climate is going to be different,” he said, “but the mission in many ways is going to be similar.” The focus of his mission, and that of the broader surge in Afghanistan, will be in counterinsurgency, as it was in Iraq.

“Even though the war in Afghanistan has been going on for a longer period of time it hasn’t been prosecuted with the same amount of focus and urgency that Iraq has, so this surge is going to be pivotal,” he said.

Sharing duties as a Marine and an elementary school principal presents its own set of unique challenges, one of which is explaining to children something as complicated as the war in Afghanistan and Mr. Halt made sure to take different, age-appropriate approaches.

“It really depends on which group of students you are talking to,” he said. “When I was talking to the kindergartners and first graders I told them I was going to go work in another country and help kids just like them someplace else. Then when I was talking with the older kids they want to know more specifics so I explain to them that my job is to support the war fighter and work with the other agencies as a liaison, which is what I expect I’ll be doing.”

Mr. Halt, who has three children — a daughter at the regional high school and two sons at Wake Forest — has also had to deal with the short notice of his call-up and the strains that has placed on his family life. When he was called up in November of 2006 he delayed telling his family until after Christmas. “I didn’t want to ruin the holidays for them, but that still gave me November and December and a little bit of January to get everything in order. This time I learned just after Christmas,” he said.

Before deployment, the greatest challenge for Mr. Halt is making sure that life continues smoothly without him, both professionally — he hopes the initiatives at school he has started will continue in his absence — and domestically.

“Once one person is removed all those little things you do as part of a family still have to go on,” he said. “So I think, how do I make it easier for my wife and kids when I’m gone? Right now that’s the hardest thing for me.”

For his students at the West Tisbury School, however, the transition has not been as difficult as it was in 2007. Ed Jerome, a retired principal from the Edgartown School who served as interim principal the last time Mr. Halt was called up, will take over as temporary principal for the next six weeks while superintendent Dr. James H. Weiss decides who will be the interim this time around.

“The kids remember last time, so they realize that this is something that I do,” Mr. Halt said. “The school and their lives continued when I went away. The other day when I was trying to comfort them it was pretty obvious that they were more interested in trying to reassure me.”