India, March 31 -- It might be difficult to imagine today but just two decades ago, the Maoist movement held large swathes of central and eastern India in its grip. Roughly a fourth of India's districts had seen Left-wing extremism in some form, and chunks of its tribal heartland were under the writ of the insurgency. Though Naxalism first took root in the north Bengal hills in the 1970s amid simmering peasant unrest and anxiety about economic inequality, a hungrier and more violent Maoist ideology had slowly spread across central India in the 1990s, reaching its peak in the 2000s and 2010s. Even after prime minister Manmohan Singh described Maoism as India's biggest internal security challenge in 2006, the insurgency only gained in stren...