That “blunder” began with Britain’s 1947 partition of its Indian colony into a Hindu-majority India and a Muslim-majority Pakistan. The status of what was then the principality of Jammu and Kashmir was left undecided. India and Pakistan soon fell to blows over it, which ended with Pakistan occupying roughly a third and India two-thirds, divided by a heavily armed and bullet-riddled “line of control.” India’s side was granted a relative degree of autonomy in exchange for accepting Indian rule.

The United Nations recommended holding a referendum to let Kashmiris decide their fate, but that never happened. In later years, Muslim militants, often backed by Pakistan, joined the fray, striking at Indian troops in Kashmir and at targets deep inside India, including a multiday killing spree in Mumbai in 2008 that left more than 160 people dead.

In this volatile stew, India’s latest action provoked instant vows of resistance. The Kashmiris are especially incensed by the lifting of a ban they had long imposed on the purchase of land by nonresidents, to prevent their land from being bought up by Indians. “There will be chaos if our identity is compromised,” vowed Mehbooba Mufti, a former chief minister of Jammu and Kashmir. In neighboring Pakistan the sabers were quick to rattle. “Pakistan will exercise all possible options to counter the illegal steps,” declared the Pakistan Foreign Ministry, while Shahbaz Sharif, the leader of the political opposition, thundered that “Kashmir is the jugular vein of Pakistan, and anyone laying a hand on our jugular vein will meet a frightful end.”

The fray is not without global implications. Under President Trump, the United States has shifted its favors from Pakistan, a longtime recipient of American aid, to India, which the administration perceives as a bulwark against China. China, meanwhile, has become an ally and financial patron of Pakistan.