A little later, Ashwatthama who was engaged in an other part of the battle field, is surprised to discover the kaurava army in disarray and running helter-skelter. Asks Kripa for the reason and is aghast at learning about his father's death, extremely angry, he avows, 'Let the earth quench its thirst with the blood of Yudhisthira, who cheated and made my father give up his fight. I can have peace only after killing the panchalas and Dhristadhyumna!'
He then invokes Naryana astra and directs it against the pandavas. This astra takes the form of different weapons and begins to destroy the pandava army. The astra also has the capacity to match the strength of the army it is against and grow in size if required. The pandava army has no answer to this astra and are feeling helpless!
It is Krishna who knows the secret of neutralising this astra, advises the pandava army to drop its weapons. The whole army complies except Bheema. The astra leaves the rest of the army alone and attacks Bheema. Krishna and Arjuna seeing this, run and pull Bheeema down. They counsel him to stop fighting, ' Do you not see the others standing without a fight. If there was a chance of winning would we have not fought?.' Once the whole pandava army stops fighting, the Narayana Astra becomes quiet. There is no further danger from it, as it can be used only once! Ashwatthama tries other astras, but Arjuna has answers to these, so a discouraged Ashwatthama gives up and returns to his camp.
While Vachana Bharata is brief about the war, Kamala's version does have more details. For instance Ashwatthama cannot understand how Naryana Astra was neutralised and did not destroy the pandavas as he had hoped.
Ashwatthama asks Vyasa, 'My lord, why did my astras fail? How could they?' Vyasa explains to him that Krishna and Arjuna are in fact incarnations of Nara and Narayana. 'You cannot either defy them or destroy them. You are trying to do the impossible. Your father has reached the heavens, there is nothing for you to grieve. Go home, my child and think of tomorrow!'
The concept of Astras itself is thought provoking.
In Hindu mythology an astra (Sanskrit: अस्त्र) was a supernatural weapon, presided over by a specific deity. To summon or use an astra required knowledge of a specific incantation/invocation, when armed. The deity invoked would then endow the weapon, making it impossible to counter through regular means. Specific conditions existed involving the usage of astras, the violation of which could be fatal. Because of the power involved, the knowledge involving an astra was passed from a teacher to a pupil by word of mouth alone, and only following the establishment of the student's character. Certain astras had to be handed down from the deity involved directly, knowledge of the incantation being insufficient...wikipedia
More or less a safe system, even if we come across some situations wherein a diety does bestow these Astras to undesirable characters. But luckily for humanity, there is always a Vishnu or a Shiva saving mankind at the nick of time!
Today Proliferation of Nuclear weapons is a serious concern. Again thanks to almighty, it was only used against one country, twice unfortuantely, and after that there have been confrontations and threats, but so far no one has pushed the button! But more and more are into making Nuclear weapons! They neither need the blessing of a guru or a major diety. They can invent or steal the technology!
Again I read that India was the largest buyer of armaments last year! Perhaps placating gods would have been cheaper and more productive.