We know that a lot of top US military types have lost their passion for the F-35 light attack bomber. A recent report from the Pentagon's Center for Strategic and Budgetary Assessments put it this way:
[It] will not be able to operate effectively or efficiently against anti-access/aerial-denial (A2AD) weapons and doctrine being developed by China and other adversaries.
Some time ago it became obvious to me that stealth warplanes, other than strategic bombers, were better as defenders than as attackers. Which leads us to this thing, China's first stealth fighter, the J-20. By American standards it's not highly stealthy. Like the F-35 it's limited to frontal aspect only stealth cloaking. But for its intended role, to counter an American stealth attack, it's more than enough.
Aviation Week's Randy Sweetman explains how the J-20 is a stealth killer.
The J-20 design, therefore, is an air-to-air fighter with an emphasis on forward-aspect stealth, efficient high-speed aerodynamics and range, with a modest internal payload and more than adequate agility for self-defense. The aircraft has considerable potential for development, because of its currently unsophisticated engines. But it is also large and expensive, and continued development of the J-10B shows that China plans to maintain a high-low mix of fighters for a long time to come.
This concept fits very well into an anti-access/area-denial strategy given China’s regional geography and the fact that the nation’s military and geopolitical ambitions are focused on the China Sea and its surrounding island chains. The U.S. has committed its armed forces to concentrate much of their funding on tactical fighters with a combat radius of 600 mi., much less than the distance from their bases to targets on the Chinese mainland, and has persuaded its allies to do the same.
As a result, operations are almost entirely dependent on two groups of aircraft: tankers and large intelligence, surveillance and reconnaissance (ISR) aircraft with long endurance. Under the “distributed control” concept favored by U.S. Air Force commanders as a hedge against electronic warfare, including cyberattacks, the ISR aircraft also have a control-and-communications function. However, both tankers and ISR aircraft are vulnerable to attack, and maintaining a defensive combat air patrol (CAP) over them at long range is also difficult.
The J-20’s primary mission, therefore, may be to use stealth and speed to break through the CAP and threaten vital tankers and ISR platforms. Its range gives it a “long lance” advantage—if the tankers, ISR aircraft and escorts have to stay out of the J-20’s range, the tactical aircraft that they support will not have the airborne radar cover or range needed to reach their targets.
Next week the Chinese are scheduled to demonstrate their second, stealth warplane, the J-31, to the public at an airshow in Zhuhai, near Hong Kong. The J-31 looks eerily similar to the F-35 which some chalk up to the Chinese theft of computer data from American and British defence contractors.
A report from the US Naval Institute newsletter says American pilots fear that the J-31 could prove to be the equal of America's F-22 and F-35.
“They’re still in the glossy brochure phase of development, so they still look ten feet tall and bulletproof,” one senior U.S. fighter pilot familiar with the F-35 program told USNI News. “I think they’ll eventually be on par with our fifth gen jets — as they should be, because industrial espionage is alive and well.”