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अथ चेत्त्वमिमं धर्म्यं संग्रामं न करिष्यसि ।
ततः स्वधर्मं कीर्तिं च हित्वा पापमवाप्स्यसि ॥२- ३३॥

atha chettwamimaM dharmyaM saMgraamaM na kariShyasi ।

tataH swadharmaM kiirtiM cha hitwaa paapamawaapsyasi ॥२- ३३॥

Source: Automatic ITRANS Transliteration

Now, if this righteous battle you will not fight,
Then, losing your integrity and fame, you will incur sin.

Source: Milind S. Pandit

If you will not fight this righteous war, then you will fail in your duty, lose your reputation, and incur sin.

Source: The Bhagavad-Gita: The Sacred Song

If, however, you do not fight this religious war, then you will certainly incur sins for neglecting your duties and thus lose your reputation as a fighter.

Source: Bhagavad Gita As It Is