Security against defeat implies defensive tactics; ability to defeat the enemy means taking the offensive.
不可胜者,守也;可胜者,攻也。
真爱如血 第2季
How are we gonna work on our defensive tactics if we can't even climb a fence?
如果我们连一个栅栏都爬不过去还谈什么防御策略?
孙子兵法
The different measures suited to the nine varieties of ground; the expediency of aggressive or defensive tactics; and the fundamental laws of human nature: these are things that must most certainly be studied.