Ithihasams are replete with instances of many legends being forced to support adharma or a non rational act, just to uphold a promise given by them.
Take the case of Dasaradhan. He gave a boon to his wife Kaikeyi for showing presence of mind during a critical battle, which she redeemed at a later stage with tragic consequences. On the eve of Sreeraman's coronation as Crown Prince, she used the boon to insist that Dasaradhan banish Rama for 14 years to the jungle and to crown her son Bharathan as Crown Prince. Much against everyone's wish, including his Prajas, he had to accede to Kaikeyis wish and send Sreeraman to the Jungle. Did he forgo his responsibility to his Country and People for a boon given long ago, but was totally unjust and asked for a selfish purpose? Was his promise more worth than what was good for the Country?
Young Devavrata took a Bhishma Sapadham so that his aged father Shantanu can marry a young girl, Satyavathi. He relinquished his right to be the King and vowed to protect Hastinapuram against any usurper. Should he have done this to satisfy the whim of an aged man, who thought only about his personal pleasure? Did not the Country and people lose out the wisdom of a great warrior like Devavrata (Bhishma)? And much later, he was forced to side with the Kauravas, against Pandavas in the Kurukshetra war, thereby fighting against an Army that was waging a war for Dharma.
Karnan was known for his Dana Seelam. Indran, knowing fully well this sterling quality of Karna, comes in disguise and asks him to donate his Kavacham and Kundalam. Knowing his life will be in peril in the imminent War, Karnan does offer them as alms to Indra, thereby letting down himself, his close friend Duryodhana and the Kauravas. Karnan also gave a word to his mother Kunti that he will not kill any of his brothers other than Arjuna. Though he had chances to kill the other four, he let them off each time, honouring his word, but falls prey to Arjunans arrow in tragic circumstances. Another case of mistaken priorities perhaps?
While I am one for honouring one's word (what are we, if we cannot honour our words!), it should not be at the expense of the greater benefit to the mankind, or ones Country or ones Organization or ones Family.
Did not Krishna ask Yudhishtira to utter 'Aswathama hatha: Kunjara:' which ensured Drona keeping his Weapons down, so that Dhrishtadhyumnan can kill him? This turned the war in favour of Pandavas and greater good prevailed.
