《北史·列传·卷九》
两人一向有深仇，这一来势力均衡，谁也不能首先发难，可说是防御边患的上策啊！
两人素有深仇，其势莫能先发，此御边之上策。
The two have always had a deep hatred, and now that their strength is balanced, neither of them can attack first. It can be said that it is the best strategy to defend against border troubles!
<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: 两人素有深仇，其势莫能先发，此御边之上策。 Modern: 两人一向有深仇，这一来势力均衡，谁也不能首先发难，可说是防御边患的上策啊！ [/INST] The two have always had a deep hatred, and now that their strength is balanced, neither of them can attack first. It can be said that it is the best strategy to defend against border troubles!</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: 两人素有深仇，其势莫能先发，此御边之上策。 Modern: 两人一向有深仇，这一来势力均衡，谁也不能首先发难，可说是防御边患的上策啊！
user
The two have always had a deep hatred, and now that their strength is balanced, neither of them can attack first. It can be said that it is the best strategy to defend against border troubles!
assistant