By the authors' count, therefore, "China's territorial interests overlap with those of 24 other governments".
China regularly holds exercises in the area, where its territorial claims overlap with Vietnam, the Philippines, Malaysia, Brunei and Taiwan.
Beijing has repeatedly blamed the United States for stirring up trouble in the South China Sea, where its territorial claims overlap in parts with Vietnam, the Philippines, Malaysia, Brunei and Taiwan.
Still, every country is aware that official Chinese maps still show its national boundaries overlapping territorial waters claimed by others.
This is an important issue in the complex overlapping territorial disputes in the South China Sea, where China is reclaiming land in contested areas.
The promised code of conduct itself has still not materialised let alone agreement even on a mechanism for tackling the complex mesh of overlapping territorial claims.
Tensions have been rising in the South China Sea, home to important international shipping lanes, due to overlapping territorial claims and rapid building of artificial islands by China that has been criticized by Tokyo and Washington.
But its zone is controversial because it includes the skies over islands known as the Senkaku in Japan and Diaoyu in China, which are the subject of a long-running territorial dispute, and overlaps zones established by Japan and South Korea.
The United States and Japan are also eager to counter China's growing military might in a corner of the world saddled with overlapping territorial claims, unresolved conflicts and lingering historical animosity.
The region has seen tension due to overlapping territorial claims involving the Philippines, China, Vietnam, Malaysia, Brunei and Taiwan.
