Camp Leatherneck is the sprawling base in Afghanistan’s Helmand province from which the Marines surged against the Taliban in 2009. They turned over the keys Sunday in a ceremony that also marked the handover of Camp Bastion, an adjacent British-run airfield.

Helmand province was the epicenter of President Barack Obama’s surge against the Taliban. The Marines focused on it so completely that some dubbed the patch of desert “Marine-istan.”

After they had turned the tide in Helmand, the Marine Corps commandant, Gen. James Amos, said in 2011 that it was time to begin handing over control to the Afghans, whose ability to handle the Taliban and unify their fractured country would ultimately decide the outcome of the U.S. chapter of this war.

“We can’t stay in Afghanistan forever,” Amos said.

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The Marines point with pride to their successes in Helmand. But some question whether those gains will be sustained after the Marines are gone and the Taliban seek another comeback.

Just two years ago at the British-run Camp Bastion, adjacent to Leatherneck, the Taliban pulled off arguably their most stunning attack on a NATO base of the entire war: Fifteen insurgents breached the camp’s security perimeter and, using grenades, machine guns and other light weapons, killed two Marines and destroyed or heavily damaged nine aircraft.

The Marines are now departing as the U.S. prepares to complete its combat mission in December and transition to a NATO-organized follow-on mission, called Resolute Support, to train and advise Afghan forces. There are still a little over 21,000 American troops in Afghanistan, down from a 2010-2011 peak of 100,000.

The saga of Marines in southwestern Afghanistan began with the controversial decision to make Helmand the main focus of Obama’s initial surge of American troops in early 2009. Some believed it should instead by the neighboring province of Kandahar, whose far bigger population seemed to make it of greater strategic importance.

In his book, “Little America: The War Within the War for Afghanistan,” author Rajiv Chandrasekaran wrote that the consequences were profound.

“By devoting so many troops to Helmand instead of Kandahar, the U.S. military squandered more than a year of the war,” he wrote.

“Had the initial contingent of Marines been sent to Kandahar, it could have obviated the need for a full 30,000-troop surge later that year, or it could have granted commanders the flexibility to combat insurgent havens in eastern Afghanistan much sooner, allowing them to meet Obama’s eventual withdrawal deadlines without objection.”

Helmand was not the Marine Corps’ first plunge into Afghanistan. In November 2001, Marine Brig. Gen. James Mattis led a contingent of Marines and soldiers, dubbed Task Force 58, into southern Afghanistan in an air assault that established the first conventional U.S. military presence in the country.