New Delhi, Feb. 17 -- Humans tend to forget history's harsh lessons quickly. Those fanning communal tensions today conveniently forget that such attempts in the past have ended in devastation. The sentence served last week on Sajjan Kumar, a former Congress leader from Delhi, has not only revived memories of the dark days of the riots of 1984 in the wake of the assassination of Indira Gandhi but also forced us to reflect on our present-day world that reeks of hate.

Kumar was convicted of the murder of Jaswant Singh and his son in a case filed by Jaswant's widow. Kumar hadn't been arrested for long, and the police had even filed a "closure report" in the case at one point. But now the law finally has caught up with him. Till now Kumar has...