The haiku starts the same but has three different last lines, one corresponding to each general. Note that in translation to English the 5-7-5 pattern of the haiku is lost.
If you don't sing
...I'll kill you.
...I'll make you sing.
...I'll wait for you to sing.
So one general was an angry man and quick to violence. The second was strong and quick to impose his way on the world, and the third was patient.
The haiku is used as a metaphorical lesson by the Japanese, as you can probably guess which general's troops won the long lasting war? The patient one, of course, and under the family of the general Japan had over 200 years of peace during the Edo period.
This all made me think about my approach to environmental stewardship and frustrations about the forces aligned against a sustainable landscape for the future in our production areas of the world. Certainly, a little patience might be useful as we work to find solutions to our society's needs and our ecosystem's challenges.