Might in The Protection of Right
Sage Vishwamitra, Sri Rama and Lakshmana resumed their journey. The Sage told them the history of Siddhashrama where Lord Vishnu Himself stayed for practising austerities, (tapasya) and concentration of mind (yoga)before being born as Vamana for subduing the Asura King Bali.
Sage Vishwamitra's own ashrama was within the territory of Siddhaashrama. All the hermits of that place gladly welcomed Vishwamitra and the two princes of radiant personality. Sri Rama now requested the Sage to commence his sacrifice(Yajna). The next morning the Sage began his six-day Yajna, protected by the two bowmen, Sri Rama and Lakshmana.
The sacrifice (Yajna) was performed chanting the sacred texts in all accuracy.
Then the two Rakshasas, Maricha and Subahu and their followers, with their magical powers rained blood, flesh and pus on the sacrificial site.
Sri Rama was first disinclined to kill the perpetrators of ruin. As their nuisance continued unabated, Sri Rama had to deal with them. He cahnted the texts invoking Manu and aimed a missile at Maricha. The missile threw Maricha into the far away ocean.
Then Sri Rama invoked Agni and aimed a missile at Subahu. The wicked demon's chest was pierced and he fell dead. With the missile presided over the Vayu, Sri Rama drove away the rest of the demons, gladdening the hearts of the sages now greatly relieved. Vishwamitra's mission-Yajna was successfully completed.
The royal Sage praised the princes for their success in protecting the Yajna, using the missiles proerply and thus helping to attain fulfilment of the sacred work. The place truly became a Siddhashrama, an abode of success and achievement.
The Lord uses punishment as the last resort after trying oter methods of persuasion such logical arguments, gifts for appeasement and threat.