"I thought that because fewer wolves meant more deer, that no wolves would mean hunters' paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view."
Aldo Leopold
The US, the UK, and most of the other space faring nations (Italy, France, Japan, India, etc) readily share data with the whole world. Everyone knows where we're going, what we're doing, and in the event of having spacecraft crash into something (be it the moon or a comet) word is usually sent out for everyone to watch, record, and analyze the event.
No one had a clue the Chinese were going to do this, and if they had, you can bet that a whole battery of telescopes would have been watching to glean whatever scientific information they could. The Chinese do not play well with others.
It was in a stable orbit, and had been for 16 months. I'm guessing it was a deliberate act. Why is the question.
You're probably right, but I guess what I was implying is that they could have been attempting some other type of maneuver, screwed up, and had no choice. Maybe it was easier, or more strategically important, for them to crash it into the moon rather than admit to some other kind of failure. Either way, they're not playing well with others.