The Vatican excommunicated four bishops recently ordained by the Chinese "Church." Really, it's an underutilized tool.
But the background is even more interesting: the Vatican's upset with China because they had agreed in low-key discussions that China would only recognize Vatican-authorized bishops. That understanding would have been a key step toward reestablishing diplomatic relations.
And China broke the agreement within days. I know the Vatican must walk a narrow line here between tough love and gaining access to minister to its flock. But that's what happen when you rely on the word of despots.