It was a gesture that was equal parts diplomacy and theatre: Thai Prime Minister Anutin Charnvirakul coaxing a melody out of a traditional Vietnamese t’rung xylophone at a Hanoi state banquet on Monday.The real music, however, had been made in the meeting rooms.Two days of talks between Anutin and his Vietnamese hosts produced a pledge to nearly double bilateral trade to US$25 billion within four years – and eventually to double it again. Supply chains would be stitched together across electronics and semiconductors; trade barriers would fall.Behind the bonhomie lay a hard-nosed reality: battered by US tariffs, Middle East turmoil and soaring commodity prices, Thailand and Vietnam have decided they are stronger as a pair.Anutin Charnvirakul smiles after playing a traditional Vietnamese “t’rung” xylophone at a state banquet in Hanoi on Monday in this still from a social media video. Photo: FacebookThe summit followed Vietnamese President To Lam’s own debut visit to Bangkok barely a fortnight earlier, marking a rare set of back-to-back meetings between the leaders of Southeast Asia’s second and third-largest economies.“Both countries face a shared external shock,” said economist Pavida Pananond, an international-business professor at Thammasat Business School in Bangkok, citing “the fracturing of the rules-based trading order”, reconfigured global supply chains and intensifying US-China competition.