To be in an untenable position, having no basis for either advancing or retreating; caught in a dilemma; at a loss as to what course to take.
面对这个突发的紧急状况，他感到进退无据，一时间不知如何是好
Facing this sudden emergency, he felt caught in a dilemma, momentarily at a loss as to what to do.
Next Idiom