《新唐书·列传·卷十九》
如让其逃脱，守险于山谷再行讨伐就很难取胜了。 
若遁岨山谷，克之实难。 
But if we allow them to escape and set up camp in the difficult mountain terrain, it may be very difficult to defeat them." 
<s>[INST] For each of the following sets of Classical Chinese and Modern Chinese sentences, provide an English translation that captures the essence of both: Classical: 若遁岨山谷，克之实难。  Modern: 如让其逃脱，守险于山谷再行讨伐就很难取胜了。  [/INST] But if we allow them to escape and set up camp in the difficult mountain terrain, it may be very difficult to defeat them." </s>
For each of the following sets of Classical Chinese and Modern Chinese sentences, provide an English translation that captures the essence of both: Classical: 若遁岨山谷，克之实难。  Modern: 如让其逃脱，守险于山谷再行讨伐就很难取胜了。
user
But if we allow them to escape and set up camp in the difficult mountain terrain, it may be very difficult to defeat them."
assistant