BEIJING, Dec. 30 -- China's recent moves to defend its sovereign territories in the South China Sea make sense, a U.S. scholar has noted.

China has described the issue in the Nansha Islands as a "core interest" because it involves sovereign territory, and it "is only a statement of the obvious," said Greg Austin, a professorial fellow with the EastWest Institute in New York.

"Any assumption that China has somehow expanded its maritime claims because it now feels more powerful is not borne out by the facts," Austin said in an article published recently on the website of The National Interest, an American bi-monthly international affairs magazine.

"One of many things that have changed about the disputes is China's willingness to act robustly, as most states would, to defend pre-existing sovereignty claims that have been in place ...," said Austin, who is also a visiting professor at the University of New South Wales Canberra.

"China's primary motivation in recent South China Sea military activities, then, is to defend what it sees as its island territories which neighboring countries have attempted to usurp," the scholar said in the article entitled "Why Beijing's South China Sea Moves Make Sense Now.