The Indian prime minister, Narendra Modi, is visiting Vietnam – en route to the G20 summit in Hangzhou – in a gesture aimed squarely at the Chinese leadership.
India is seeking to highlight its growing strategic ties with Vietnam, which it sees as an important counterweight to the growing territorial ambitions of China.
Mr Modi will meet all the top Vietnamese leaders, with military cooperation and weapons sales high on the agenda.
Both India and Vietnam are pursuing multilateral diplomacy in an effort to respond to the military threat from China, with both countries seeking support from the United States and Japan as well as from each other.
India is spooked by China’s “String of Pearls” strategy to develop military bases across the Indian Ocean, from Pakistan and Sri Lanka to East Africa.
In apparent response, it has been showing a growing interest in the South China Sea in defiance of China’s territorial claims there, sending naval patrols and seeking oil exploration contracts.
Mr Modi is expected to discuss plans to give Indian ships more access to Vietnamese ports, including the key strategic base at Cam Ranh Bay.
Vietnam wants to finalise a deal to purchase patrol boats from India and to purchase Indian and Russian developed BrahMos missiles, which could be highly effective against Chinese ships should confrontation flare into conflict in disputed waters.
India publicly backed the recent legal ruling at The Hague which rejected many of China’s claims to vast expanses of territory in the South China Sea.
The Vietnamese president, Tran Dai Quang, warned this week that there would be no winners in the event of war.
In one of Vietnam’s most outspoken statements so far on the dispute with China, Mr Quang told a forum in Singapore that maritime security, freedom of navigation and over flight were increasingly at stake.
Vietnam is anxious to avoid an open breach with China and continues to walk a careful diplomatic path between Beijing and Washington.
However, Hanoi is preparing for the worst as China steps up its territorial claims, emerging as one of the world’s most active arms purchasers in recent years and building stronger ties with countries that make little secret of their aims to contain the growing might of Asia’s largest economic and military power.