Literally translated, it would be something like: भयं न कथंचन विकल्पः / bhayaṃ na kathaṃcana vikalpaḥ
A related, and probably more idiomatic, way of saying it would be: निर्भयं खलु निर्विकल्पम् / nirbhayaṃ khalu nirvikalpam (Fearlessness is really without an alternative)
However, there is a nice सुभाषित/aphorism (couplet #56 in Max Müller's edition of the Hitopadeśa) that would be quite appropriate in this context:
तावद्भयस्य भेतव्यं यावद्भयमनागतम्।
आगतं तु भयं वीक्ष्य नरः कुर्याद्यथोचितम्॥
tāvad bhayasya bhetavyaṃ yāvad bhayam anāgatam
āgataṃ tu bhayaṃ vīkṣya naraḥ kuryād yathocitam
i.e. Fear is to be feared as long as it has not arrived. When it arrives, one should look at it, and take the necessary actions.