On a day when US President Donald Trump hailed India's unity, diversity, communal harmony, respect for rule of law and dignity of every human being, communal rioting in Delhi posed searching questions on all those fronts. Delhi Police, in particular, has much to answer for. Woefully unprepared for the violence that raged across northeast Delhi, the police put some of its own personnel's lives at risk by deploying too few men to take on rioters. Quite a few videos also pointed to partisan conduct by police. Ominous signs were visible as early as Sunday noon when BJP leader Kapil Mishra led a mob supporting the Citizenship Amendment Act to confront anti-CAA protesters and both sides pelted stones in the hours following Mishra's provocative remarks. At least ten lives have been lost and scores injured including journalists in the line of duty, because of Delhi Police's monumental incompetence. At the first signs of trouble, a more professional police force would have intensified patrolling, convened peace committees and ramped up intelligence. Sadly, not in the national capital. The Union home ministry, exercising administrative control over Delhi Police, cannot skirt responsibility. Despite several failures over the course of his blemished stint as police commissioner, it granted Amulya Patnaik an extension last month. The most ghastly among these saw students of famous campuses like JNU and Jamia coming under attack with police facing charges of omission and commission. Even yesterday, early media reports pointed to police missing in action in some riot affected neighbourhoods. The spectre of the 1984 anti-Sikh riots has always loomed uncomfortably over the capital city and for this reason many believed it would not permit another large-scale riot. More so on a day when India would like to showcase its capabilities as a leading democratic power. Politicians must introspect for this failure, which has shamed India before the world. Not only has Delhi Police been badly led, the role of politicians in sowing the current climate of discord, with incendiary rhetoric polarising communities and casting opponents as traitors, is reprehensible. East Delhi MP Gautam Gambhir has rightly demanded action against those making provocative remarks irrespective of party lines, including his party colleague Mishra. The Modi government must restore order in Delhi and correct the creeping distrust of state agencies in minority communities. The Supreme Court taking note of CAA's discriminatory provisions would also help.