But is China really so cowed by the West that it is afraid of announcing its own achievements? If so, what does that say about China's confidence?
Only the Western-minded feel that being quiet means being cowed and that being loud means being confidence. In the east, the silent chicken eats the most grain; talking too much is a sign of weakness and lack of substance in Chinese culture. By going into steath mode, China is showing its hostility to the West, that they will not have the privilege of a Chinese show and tell because those are for friends. It says that China's confidence is sky high as the inconspicious onlooker with a sly grin rather than the overcompensating loudmouth or the overly gregarious and accomodating small potato hoping to curry the favor of some big bosses.
Or does it pursue "yin" because it wants to give the illusion it has more achievements than it actually does? For the outsider, there is no way to tell the difference.
One simply needs to analyze that every single endeavor that China embarks on, it succeeds. And also that China always moves faster than the US and the last time China made a serious entry, it was already ahead of the US. It's easy to tell for those of us who understand Chinese macro-trends that China is far ahead in the supercomputer race.
But in my view, China tends to over-announce and under-deliver. For instance, the C919 was supposed to be delivered by 2021.
Since your view is always wrong, that's good. China always keeps quiet about what it can really do before blowing everyone's minds at the last second. For example, there is the enveiling of the J-20, the Sunway Taihu Light, the launch of China's quantum satellite, etc... They are all examples of China hiding its progress until the last moment. In contrast, the US enthusiastically announces huge projects like the railgun and then abandons it saying it'll settle for a munition reshaping instead. China, on the other hand, provided no fanfare to its railgun progress until a ship-mounted one was seen at sea, shocking the US that China was ahead of it despite keeping its mouth shut.
C919, unfortunately, has much Western cooperation for an internationally commercially-competitive project, which is why it's buried in paperwork and beaurocracy. Nonetheless, it's still faster than Western projects (infrastructure comes to mind at the top of the very long list) that often move at a snail's clip due to indecisiveness and infighting and end up dead in the water.
I only point out that the line of argumentation used by the previous poster is chasing its own tail.
IF China announces and proves an achievement, then: "China is so great! They can do it!"
IF China DOES NOT announce and prove an achievement, then: "China is so great! They can do it (only they can't show it bc terrified of America)!"
No matter what the China optimist gets to reach the same conclusion. No matter what China never fails. It's a non falsifiable hypothesis, a catch-22 akin to a religion. Except reality doesn't work like that.
This is really only a problem for those who lack the mental capacity to do a big picture analysis. Even though China can move in a different pattern depending on the situation, the conclusion is always the same to us, that China is succeeding and will succeed, because historically, it always has. Only those with a very limited scope of mind but an unlimited desperate hope for China's failure endlessly hunt in vain for small things to cast doubt that China might fail this time.