No one would mistake them for best of friends. But US president Joe Biden, the son of blue-collar Scranton, Pennsylvania, and Indian Prime Minister Narendra Modi, who rose from tea seller’s son to premier, have developed a relationship based on mutual respect of their scrappy backgrounds and pragmatism about the shared challenges their two countries face. Biden is hosting PM Modi for a state visit this week as he looks to tighten his relationship with the leader of a nation of 1.4 billion that the US administration sees as a pivotal force in Asia for decades to come. The pomp-filled...