The twenty-fifth of the Book of Changes' sixty-four innate hexagrams was the Hexagram of Innocence. The idiom "an unwarranted disaster" originated from this hexagram.
"Unwarranted" meant reckless action, moving without thought. Innocence meant not acting recklessly or moving rashly, yet thunder still roared, lightning still flashed, and disaster still descended.
That was not called bad luck. Human calculations could not surpass Heaven's. You might think your conduct had been proper, but others might not see it that way.
During the Battle of Changping between Qin and Zhao, there was a general named Zhao Kuo. He excelled at "conducting warfare on paper." At the time, the veteran general Lian Po relied on the mountain terrain to build sturdy fortifications and hold his ground, intending to wear down the Qin army until it retreated without a battle. But Zhao's nobles could not wait any longer.
First, Zhao's weather was cold and its land infertile, making it impossible to stockpile much grain.
Second, Zhao's envoys went to King Min of Qi to borrow grain, but King Min ignored the principle that "when the lips are gone, the teeth grow cold" and refused to lend Zhao any food.
Perhaps he wanted to let "the snipe and clam contend while the fisherman profits," waiting for Qin and Zhao to exhaust their national strength in war before Qi State attacked them both.
Or perhaps he still remembered Su Qin. It was this man from Yan who had zealously incited King Min of Qi to make enemies everywhere and become the target of public scorn.
Su Qin had studied under Guiguzi of Qi State, but Duke Wen of Yan had been the first to recognize his talent. Even men like Su Qin and Zhang Yi had once suffered from unfulfilled ambitions.
Talent was a complicated matter. If