Provoking a War

Narada to Yudhistira said,

This, O sinless one, that I am about to tell thee is unknown to the very gods. Listen to me,
O mighty-armed one, as it befell in former days. 

1. How all the Kshatriyas, cleansed by weapons should attain to regions of bliss, was the question. 
2. For this, a child was conceived by Kunti in her maidenhood, capable of provoking a general war. 

http://www.sacred-texts.com/hin/m12/m12a002.htm