Bhishma was forced to participate and be on the side of the Kauravas in the Mahabharata War due to several factors rooted in his vows, his sense of duty (dharma), and his loyalty to the throne of Hastinapura. Here are the key reasons:
Vow of Loyalty to Hastinapura: Bhishma had taken a solemn
vow to protect and serve the throne of Hastinapura. This vow was made when he
renounced his claim to the throne to ensure that his father, King Shantanu,
could marry Satyavati. By this vow, Bhishma committed himself to the welfare of
the kingdom, irrespective of who sat on the throne.
Obligation to the Kuru Dynasty: As a member of the Kuru
dynasty, Bhishma felt an obligation to support the ruling king. At the time of
the war, Dhritarashtra was the king, and his son Duryodhana was the crown
prince. Bhishma's duty to the Kuru lineage and the reigning monarch bound him
to support them.
Respect for Dhritarashtra's Authority: Despite knowing the
unrighteousness of Duryodhana, Bhishma had a profound respect for
Dhritarashtra, the blind king. Dhritarashtra’s decision to support his son
Duryodhana meant that Bhishma, bound by his duty, had to align himself with
their side.
Elder Statesman Role: Bhishma was one of the eldest and most
respected figures in the Kuru court. His participation was also seen as an
attempt to maintain some semblance of order and justice. He hoped that his
presence might restrain some of Duryodhana's excesses and lead to a more
honorable conduct of war.
Commitment to Dharma: Bhishma’s understanding of dharma
(duty/righteousness) was complex and multifaceted. He believed in adhering to
his commitments and vows, even when they placed him in morally challenging
situations. His commitment to his personal dharma often conflicted with the
larger moral righteousness but he chose to uphold his vow to serve the throne
above all.
Loyalty to His Word: Bhishma was known for his steadfastness
to his word. Once he made a commitment, he would not break it under any
circumstance. This unwavering loyalty to his promises was a hallmark of his
character and left him little choice but to support the Kauravas.
While Bhishma was personally more sympathetic to the
Pandavas and disapproved of Duryodhana’s actions, his complex sense of duty and
loyalty ultimately dictated his participation on the side of the Kauravas. This
tragic conflict of duty versus righteousness is one of the many profound
ethical dilemmas explored in the Mahabharata.