The appearance of three Chinese naval vessels firing live rounds in the Tasman Sea has caused understandable alarm in New Zealand and Australia. But this has more to do with the geopolitical context than the actual event.
In fact, the Chinese navy is allowed to conduct exercises in the Tasman and has wide freedoms on the high seas in general. So far, China appears to be acting in accordance with both the United Nations Convention on the Law of the Sea and the Code for Unplanned Encounters at Sea.
While New Zealand would have preferred more notice of the Chinese navy’s intentions, there was no obligation to provide this.