Nguyen Duc De knows at first hand how alliances can change. The former Vietnamese soldier was stationed on the disputed Spratly Islands in the 1980s, when tensions with China were high following their 1979 border war, and he used to take pot shots at the Chinese marines who approached his base, pretending to be fishermen.

When diplomatic relations between the Communist neighbours were restored in the 1990s, shooting was prohibited, he says, but, as China’s economic and military might has grown over the past decade, strains over contested islands in the South China Sea have been on the rise again.

“They’re so big and we’re so small, so what can we do?,” asks 50-year-old Mr De, who works as a security guard at a memorial to Vietnamese and Russian soldiers who lost their lives in the Spratly Islands and at the nearby naval and air base at Cam Ranh Bay in south-central Vietnam.