Battling terrorism in Kashmir, militancy in Punjab and insurgency in the Northeast, security agencies failed to notice the Maoist threat spreading across the country. By the time the enormity of the problem hit home, almost 40 per cent of the hinterland was under Maoist influence, making the then PM Manmohan Singh call it the biggest internal security challenge in 2009. Experts in the security establishment say it was already a little too late for the government to realise it.