Half a century after the fall of Saigon, the United States and Vietnam are edging towards deeper defence cooperation built on shared anxieties about China and Washington’s desire to wean Hanoi off its historical dependence on Russian arms.US Defence Secretary Pete Hegseth arrived in Hanoi last Sunday for a two-day visit, declaring that establishing stronger security ties would be a win-win.“Deeper [military] cooperation will benefit both of our countries,” said Hegseth, who had travelled to...