Of all the recent projects, this might be the only one comparable to J-20 in significance (even more than the other 20s Z/Y-20). When I was in high school, I heard about the mythical B-2 bomber. I was told it can fly undetect from continental USA to Europe to drop bombs before coming back. When I started to really follow military later on, B-2 for me remained just as mythical. The bomber that was a generation or 2 ahead of all other bombers and cost $2 billion per aircraft due to its small production run. I remember think those old H-6s to be about 3 generation behind B-2. I remember telling a friend back in 2009 that I did not think China could build something like this in the next 20 years. Now, it seems like I may have underestimated China's progress.
Back in 2005, there was a lot of talk of China buying backfires from Russia. Even as late as 2012/2013, there were rumors from Western Media that China bought Tu22M production line from Russia
. In the beginning, there were some logic in buying Tu22M due to the immediate Taiwan threat. It was laughable that this was still something that Western countries feared by 2012. Back in those early days of 2005, I remember reading from legit Chinese sources that they had no interest in Tu22M, but really did want to order Tu160. Russia did not allow them to even look at Tu-160. I guess even PLAAF did not anticipate how quickly the domestic military aviation industry would modernize. In the end, the H-6K upgrade gave them something that could provide similar fire power to Tu-95/B-52, although with less payload. Even if Russia still wanted to sell them Tu-160, I don't think PLAAF would be interested. Unlike fighter jet, strategic bombers is always something that US (to a lesser degree Russa) were ahead of other countries due to their huge investment. When PLA had limited budget, investing in bombers over fighter jet seems like a bad idea. As such, they were content with an upgrade like H-6K which gave them a worthy bomb truck while they continued to focus on more immediate cause like a 5th gen fighter jet and Y-20 platform. With larger budget and more offensive oriented philosophy, this is now the right time to develop the next generation bomber.
In my mind, this is the Apollo project for XAC and China's strategic aviation. Similar to how J-10 was the Apollo project for CAC and China's fighter jet industry. The H-6 upgrades are probably equivalent to the J-7/8 upgrades of their day. In order to catch up, China is going up at least 2 generations with this project. It will be more advanced than Tu-160 or B-1. Something as technologically advanced as strategic bomber requires all of a nation's latest technologies. You generally don't want to rely on suppliers from other countries for building strategic bombers. China would not have been capable of developing something this advanced if they started the project in the mid 2000s. Now they have the radar, avionics, engine and stealth technology to succeed. Even with that, it is a huge undertaking. I would not be surprised if this is the one project where China does not surpass people's expectations. Assuming they do put H-20 in service by late 2020s, the experience from developing H-20 would give XAC a huge boost in other future projects.
Based on the Pentagon report, it seems like H-20 will not have as much range as B-2 or B-21. I don't think that's a problem. For PLAAF's medium term goals, combat radius of 4500 km with fully weapon loads is sufficient to cover Guam (3000 km from Shanghai to there), all of East Asia, India, Southeast Asia and even Northern corner of Australia. Future upgrades of engine and material could allow it to cover even larger area. What they need is something that can fly in undetected against defended military installations without escorts, drop bombs and fly away undetected. That's something they don't have right now with H-6K, which has to rely on LACMs. LACMs are expensive and limited in supply. Large bombs are not. As I described in the Taiwan scenario, having a modern strategic bomber that can take out military bases with large amount of bombs is critical. Maybe it will not be stealthy enough to survive the most heavily defended air space, but should be LO enough to take out other military bases. That's something only US can do right now.