The main reason Imam Hussain (as) brought Ali Asghar to the enemy’s army
I assume the main reason Imam Hussain (as) brought Ali Asghar to the enemy’s army, to ask for water in order to nourish the infant—while there was very little hope that these lupine enemies would have sympathy and give the baby water-- was that Imam Hussain (as) had no other option and there was nothing he could do to help. When the Imam (as) moved about the tents, he noticed the air was filled with anguish and much commotion, this small infant’s thirst, hunger and distress had moved everyone. Hussain Ibn Ali (as) had to take the baby in his arms—although there was very little chance the enemy would give the baby a cup of water to sooth his thirst.