Note: This story has been updated to include comments from a Lockheed Martin spokesman.
Should North Korea's hostile rhetoric give way to action, the U.S. military has sent F-22 fighters to defend South Korea. These fighters carry a price tag of $143 million each, making them the most expensive in use.
That could change if the F-35 Lightning II were deployed. Yet by all indications, that won't be happening anytime soon — if at all.
According to Winslow Wheeler, director of the Straus Military Reform Project at the Project on Government Oversight, the F-35 program now costs approximately $200 million per craft.
Despite the princely sums spent on the fighter, the plane has never been used in a combat scenario —a situation that Wheeler claims is pushing up its cost, since it missed its original 2012 deployment date.
Its convoluted design, pursued by the Department of Defense, is primarily to blame for the airplane's extended stay in the development stage, according to the analyst.
"They took vertical landing design and said, 'let's make that supersonic,'" Wheller said in an interview. "But STOVL [short take-off and vertical landing] airplanes have to be short and stumpy, and supersonic airplanes like to be twin-engine, and long and fine-looking."
The DoD then tried to make it a multi-purpose fighter and bomber, an effort that Wheeler says fell short. "Those have very different design specifications," he said.
(Read more: The Most Expensive Military Programs)
He added that the decision to make the F-35 a multi-service vehicle further complicated matters. "The Navy version looks like the Air Force version, but it's 5,000 pounds heavier," he said. "Both are quite different from the Marine Corps' STOVL version." Additionally, the design limits pilot visibility.
"The pilots said they can't see to the rear, because of the way the cockpit meets the fuselage and the placement of the headrest," he said. "Seeing to the rear is essential for fighter aircraft."
So what will it cost to correct these problems? In June 2012, the Government Accountability Office released a report estimating that the revised development cost would exceed $55 billion, a 23 percent jump over previous estimates.
However, that figure pales in comparison to the projected total cost of $1.1 trillion for its entire 30-year service life, which Wheeler called a low-ball figure.
"The total acquisition plan cost is $396 billion," he said. "That report also cites the additional cost, $1.1 trillion. Add them together and you get the eye-popping $1.5 trillion figure, and those estimates assume that everything goes perfectly from here on in."
Wheeler also noted that there was still plenty of time for the price to go up.
"We're only 25 percent of the way through the initial testing, and this is the easy, laboratory testing," he said. "Real testing doesn't even begin until 2017. The date for it to be finished with additional operational testing is 2019."
(Read more: The Most Expensive U.S. Military Vehicles)
Despite all the time and money, Wheeler said that he did not expect the completed F-35 to be much of an improvement over what the military already has patrolling the skies. In fact, he said that some of the military's existing airplanes already outperform it.
"The F-16 has more range and payload, and so does the bomber version of the F-15," he said. "In fighter mode, F-16s accelerate faster and are more agile in the air."
Ultimately, he characterized the F-35 Lightning II as an expensive, ill-conceived program, and he recommended that it be mothballed.
"The smart thing to do is put these things out of their agony and initiate a properly conceived program to design a fighter and a separate air-to-ground bomber," he said.
"You need a prototype that requires competitors to produce a combat-ready airplane," Wheeler said. "We did that with the F-16 and the F-18, and those are good, successful airplanes, very cheap and extremely effective. We need to learn the lessons of those airplanes, and the F-35 shows we've forgotten those lessons."
Lockheed Martin F-35 spokesman Mike Rein disputed Wheeler's figures, saying that 38 percent of all testing is complete and the aircraft will deploy in 2017. He also said that the $200 million figure is inaccurate.
The figure is derived from a 2012 Department of Defense document which cites a procurement cost of $6.36 billion for 31 aircraft, or $204 million per plane. This includes not just the cost of the aircraft but also maintenance, parts and labor.
"When they say a Ford pickup is $20,000, if you're going to drive the truck for the next 20 years, with all the tires, spark plugs and getting it washed, it costs probably $100,000 --- but you'd never say you bought it for $100,000," Rein said in an interview.
"The jet will cost $85 million including the air frame, engine, emissions systems, concurrency and upgrades, but the price is actually $75 million."
Finally, Rein took issue with the characterization of the F-35's visibility issues, which derives from a Pentagon weapons tester who said it was almost impossible for pilots to see to the rear. "In this aircraft, you aren't looking over your shoulder," Rein said. "The helmet has a sensor that gives it a 360 degree view. "
A spokesman for the Department of Defense did not return a call or an email.
An earlier version of this story said the F-35 plane "sits idle". The F-35 is active, but has not been used in a combat situation.