Superpowers turn up the heat in their struggle for the upper hand in Asia

It was an annual event that was supposed to bridge differences. Instead, three regional powers - China, the United States and Japan - blamed each other for causing instability in the region, leaving the less powerful nations of Southeast Asia feeling caught in the middle.

And participants at the recent Shangri-La Dialogue - also known as the Asian Security Summit - say the sniping is just getting started. There's likely to be growing antagonism between China and the US as Beijing accuses Washington of cementing regional alliances to stand up to the communist nation.

Weaker nations may be forced to answer the question they sought to avoid during the cold war: which side are you on?

At the summit, the diplomatic squabbles kicked off with Japanese Prime Minister Shinzo Abe's keynote speech on May 30. He said Japan should play a greater role as a protector in the region.

Abe said Tokyo would support Southeast Asian countries with, for instance, patrol vessels, as they sought to protect their borders against incursions by Beijing. "Japan will offer its utmost support for the efforts of the countries of Asean [Association of Southeast Asian Nations] as they work to ensure the security of the seas and the skies," Abe said.

The next day, US Defence Secretary Chuck Hagel was more blunt. He accused Beijing of de-stabilising the region through intimidation and coercion.