Why is it that an extended olive branch often turns to a clinched fist of hatred?

Why is it that an extended olive branch often turns to a clinched fist of hatred?

We are one people and will act as one.
[Ger., Wir sind ein Volk, und einig wollen wir handeln.]

We are one people and will act as one.
[Ger., Wir sind ein Volk, und einig wollen wir handeln.]

A wise man hears one word and understands two.

A wise man hears one word and understands two.

We must all hang together or assuredly we shall all hang
separately.

We must all hang together or assuredly we shall all hang
separately.

The plastic virtues: purity, unity, and truth, keep nature in subjection.

The plastic virtues: purity, unity, and truth, keep nature in subjection.

Behold, how good and how pleasant it is for brethren to dwell
together in unity!

Behold, how good and how pleasant it is for brethren to dwell
together in unity!

Unity to be real must stand the severest strain without breaking.

Unity to be real must stand the severest strain without breaking.

Nothing unites the English like war. Nothing divides them like Picasso.

Nothing unites the English like war. Nothing divides them like Picasso.

Liberty and Union, now and forever, one and inseparable.

Liberty and Union, now and forever, one and inseparable.