News analysisHO CHI MINH CITY — Poland will soon host production lines for South Korean tanks. Australia is buying warships from Japan. Canada will send uranium to India, while India offers cruise missiles to Vietnam, and Brazil builds military transport planes for the United Arab Emirates.All of these deals were sealed in the past few weeks. Each one represents an attempt by middle powers to protect themselves as the conflict in Iran throttles global energy supplies, and as a high-stakes summit between President Trump and Xi Jinping of China looms.Global polls show the world has little trust in the United…