न चैतद्विद्मः कतरन्नो गरीयो यद्वा जयेम यदि वा नो जयेयुः। यानेव हत्वा न जिजीविषाम स्तेऽवस्थिताः प्रमुखे धार्तराष्ट्राः ॥

na chaitadvidmaḥ kataranno garīyo yadvā jayema yadi vā no jayeyuḥ yāneva hatvā na jijīviṣhāmas te ’vasthitāḥ pramukhe dhārtarāṣhṭrāḥ

Nor know I which for us be the better, that we conquer them or they conquer us—these, whom having slain we should not care to live, even these arrayed against us, the sons of Dhritarâshtra.

In plain words: Arjuna says he does not know which is worse, winning or losing. If they killed their cousins, the sons of Dhritarāshtra, they would not even want to go on living.