Yesterday, the head of PetroVietnam, Vietnam’s state-owned oil company, gave a briefing in response to CNOOC’s announcement of new blocks in the South China Sea.

The briefing included a map, shown below, which indicates the extent to which China’s blocks overlap with Vietnam’s.  It also shows which foreign oil companies are targeted by CNOOC’s announcement — Gazprom, ONGC, and ExxonMobil.

In other words, China is challenging three major powers with interests in the region — Russia, India and the United States.

China wants to avoid internationalizing the dispute, but CNOOC’s act is sure to achieve the opposite result by clearly engaging the interests of other powers.