A piece of military hardware plagued by cost overruns and delays may be the absolute linchpin to the Marine Corps' ability to stay relevant in the 21st century, a top general claims.

The F-35 Lightning II Joint Strike Fighter—now considered the most costly single military expenditure ever—will be essential to the brand of amphibious and expeditionary warfare the Marine Corps hopes to deliver in its new role in the Pacific, says Marine Maj. Gen. Frank McKenzie.

Its ability to conduct the kind of warfare unique to the Marine Corps will prove as useful as the V-22 Osprey, a tilt-rotor aircraft currently used by the Marines and Air Force as a hybrid helicopter and airplane, he says.

"If you're going to fight a war against an opponent who has the capability to target your fixed bases, then you're not going to be able to operate the majority your 5th-generation fighters within theater range if they can't get out of a 7,500-foot runway," says McKenzie, who runs the Corps' congressionally-mandated Quadrennial Defense Review.

"You're going to lose those fields," he adds, "so 5th-generation fighters that have the capability to operate from distributed airfields are going to become increasingly important."

McKenzie told defense reporters during a breakfast meeting in Washington that "the most revolutionary part" of the F-35B is its ability to land and take off on a short runway, or land in a hover. This means it can touch down on roads and beaches where Marines go ashore.

A plane that can take off and land just about anywhere helps to counteract an enemy's ability to target a U.S. force, he says

"If you can disperse, you can operate from a variety of other locations and confound the targeting," McKenzie says. The Marine Corps expects to have operational capability for the F-35 in the Pacific by 2017, in keeping with President Barack Obama's "pivot" to that region. This comes at a time when all of the services are drawing down from protracted wars in the Middle East and looking to how they will contribute to national defense in the coming decades.

"The F-35 is crucial to the Marine Corps' concept of future operations because it combines the vertical utility of a helicopter with unsurpassed ability to survive in airspace," says Loren Thompson, a defense expert with the Lexington Institute. Thompson points to the F-35's stealth capabilities, possessed by no other hovering fixed-wing jets, such as the Harrier.

"It is literally the only aircraft in history that combines the ability to land anywhere with stealth," he says. "The fact that it can still land without having a runway is a remarkable achievement."

The leadership of the Marine Corps is 100 percent committed to the "B" variant of the F-35, Thompson adds, perhaps more so than Navy leaders are for their version designed to operate on carriers. Marines must also plan for a reduction in their force numbers from roughly 202,000 to about 187,000 Marines.

"They believe that especially with the force shrinking, they must have the F-35 to do their job," says Thompson.