Quantico, Va: In a nondescript room on a secure floor here at Marine Corps headquarters, a cadre of civilian and military personnel are busy redefining how the service does amphibious operations.

Amid various Power Points, diagrams and computerized templates, the members of the Amphibious Capabilities Working Group have been assigned a formidable task — take one of the Marine Corps most important (and most misunderstood) missions and redefine it for a post-Afghanistan world.

“What’s changed over the last 10 years” in amphibious operations, ACWG co-chair Col. Michael Groen asked me during an interview today? Finding the answer, he added, is one of the main jobs service leaders want.

After a decade of combat in Iraq and Afghanistan, the Marine Corps found themselves being pigeonholed as a second ground army, far removed from its historical roots as a highly-mobile amphibious force.

With the wars in Southwest Asia now winding down, service leaders are now pushing hard to get the Marines back to the sea. Marine Corps Commandant Gen. James Amos made the importance of moving the Marines back to the shoreline crystal clear in a Sept. 15 letter to Defense Secretary Leon Panetta.

In that letter, the four-star general essentially tied the entire future of the Marine Corps to the success or failure of getting the service’s focus back to amphibious operations.

With that marker clearly laid down by Gen. Amos and others, it is now up to this new working group to help make that happen.

While a number of factors will play into how the Marines do that, including the financial pressures the service and the rest of DoD face, the group has taken an approach that, they say, will make this effort more than just another budget drill.

The way they’re doing that, according to ACWG co-chair Col. Christopher Naler, is by focusing mainly on what kinds of amphibious threats the Marines are likely to face in the future, and build a number of new concepts of operations around that.

The group plans to hold a series of wargames to evaluate new CONOPS for amphib missions over the next few weeks. The results will be briefed to Navy and Marine Corps leaders at the three and four-star level, Groen said.

Discussion over what types of ships, planes or helicopters — and how much they will cost — will play a part in the group’s work, according to Naler. But, in the end, “we are not going to be held hostage by a [particular] system,” he said.

Developing new CONOPS for amphibious operations could also mean getting modifying or plain getting rid of old concepts that just don’t fit on the modern battlefield, Naler and Groen said.

The iconic beach assaults on Tarawa and Inchon, which are staples of Marine Corps tradition, won’t necessarily be the best template for future amphib missions, Groen pointed out.

“There are different ways of getting [amphibious] missions accomplished,” he said, noting the advent of intelligence, surveillance and reconnaissance drones, precision weapons and advanced communications. Given these, a full-on beachfront assault may not be needed.

An attack of any kind may not even be needed, depending on what kinds of threats and in what kind of environment Marine amphibious forces find themselves in, Capt. Samuel Howard, the Navy Fleet Forces representative on the group, said.