idiom · to consider carefully and weigh the pros and cons before taking action

他在做重大决定时总是瞻前顾后，务求万无一失。

idiom · to be overcautious and indecisive; to hesitate out of fear or doubt

既然机会就在眼前，你就不要再瞻前顾后，犹豫不决了。

idiom · to look forward and back literally or to survey a situation from all angles

他在昏暗的巷子里瞻前顾后，显得十分警觉。