We had a good run, my friends.

Alternate headline: “All Pentagon budget cuts canceled.”

Decorated Navy fighter pilot Matthew “Whiz” Buckley, a Top Gun graduate of the Navy Fighter Weapons School who flew 44 combat missions over Iraq, says, “It’s probably leaps and bounds above where we are, and that’s terrifying.”

“As a former Navy fighter pilot, going up against something that’s stealthy, highly maneuverable and with electronic systems more capable than mine — that’ll keep me up at night,” said Buckley, now chief strategy officer at Fox3 Options LLC…

Richard Fisher, a senior fellow on Asian Military Affairs at the International Assessment and Strategy Center, a Washington-based security think tank, says Chinese officials have said that their program is aimed at competing with the F-22 Raptor.

“From what we can see, I conclude that this aircraft does have great potential to be superior in some respects to the American F-22, and could be decisively superior to the F-35,” said Fisher…

Experts say it’s hard to say exactly what the J-20’s capabilities are, especially in a fire fight — but offered a dire prediction: “With China having a fifth generation fighter, the U.S. will lose F-22s faster than previous estimates.”

Mitigating factors here? First, and most obviously, in an age of semi-austerity, defense specialists have a financial incentive to tout every threat as an existential one. With the GOP ready to slash budgets and Boehner insisting that Defense is on the table, a Chinese super-fighter is a sweet way to keep the money flowing. Second, even if this is a major advance, there are reasons to believe that it’s not — yet — a major issue for the Air Force. It’s one thing to design an advanced fighter, it’s another thing to equip it with the parts it needs and to get it ready for battle:

It’s not obvious from the grainy photos of the J-20 what engines the plane currently uses, but it’s probably safe to assume they’re Russian AL-31Fs—still the best engines China reliably has access to. However, the AL-31F is clearly inadequate for the apparently heavy J-20. Even the up-rated 117S version of the AL-31F ‘would likely not be sufficient to extract the full performance potential of this advanced airframe,’ Kopp and Goon wrote. To perform at its best, the J-20 will probably need purpose-designed motors. And developing those could take a long, long time.

Equally vexing to Beijing’s aerospace designers and military planners are the sophisticated electronic, conceptual and human systems required in and around a modern fighter aircraft in order for that aircraft to deliver a useful military effect.

Richard Aboulafia, an analyst with the US Teal Group, told the Internet trade publication Defense Tech that a modern fighter requires at least 11 supporting systems to be effective, including but not limited to sound mission planning, a talented and disciplined pilot, good maintenance personnel on the ground, accurate weapons, an advanced radar and other electronic systems inside the aircraft plus ‘off-board’ radar detection provided by purpose-built command-and-control planes and the reliable ministration of an aerial tanker.

Of all the systems required by a modern fighter, Beijing has mastered just one, Aboulafia said—and that’s the airplane’s physical structure itself, minus the engines.

That’s from defense specialist David Axe, making the case for skepticism. Even so, some military analysts tell him that if/when China figures out how to build the right engine, look out: “Any notion that an F-35 Joint Strike Fighter or F/A-18E/F Super Hornet (flown by the U.S. Navy and Australia) will be capable of competing against this Chengdu design in air combat, let alone penetrate airspace defended by this fighter, would be simply absurd.” Likewise, an LA Times survey of defense experts finds an “emerging consensus” that, at the very least, China has “closed the capabilities gap” enough to pose a threat to U.S. action in the Pacific. The silver lining here, if you can call it that, is that by the time the J-20 is ready to roll out for battle, it might be a minor weapon given the new realities of warfare. See this Danger Room piece from a few days ago about where the real action is: Cyberwarfare and space weapons and sharks with frickin’ laser beams on their heads.

Update: Needless to say, the “leaked” images of the fighter almost certainly weren’t leaked.