Ernst Lissauer (1914): The Hymn of Hate:

French and Russian, they matter not,
A blow for a blow and a shot for a shot.
We love them not, we hate them not,
We hold the Weichsel and Vosges gate. 

We have but one and only hate,
We love as one, we hate as one,
We have one foe and one alone—ENGLAND!

He is known to you all, he is known to you all.
He crouches behind the dark grey flood,
Full of envy, of rage, of craft, of gall,
Cut off by waves that are thicker than blood.

Come, let us stand at the Judgment Place,
An oath to swear to, face to face,
An oath of bronze no wind can shake,
An oath for our sons and their sons to take.

Come, hear the word, repeat the word.
Throughout the Fatherland, make it heard.
We will never forego our hate.

We have all but a single hate,
We love as one, we hate as one,
We have one foe and one alone—ENGLAND!

In the Captain’s Mess, in the banquet hall,
Sat feasting the officers, one and all,
Like a sabre blow, like the swing of a sail,
One seized his glass and held high to hail;
Sharp-snapped like the stroke of a rudder’s play,
Spoke three words only: “To the Day!”
Whose glass this fate? 

They had all but a single hate.
Who was thus known?
They had one foe and one alone—ENGLAND!

Take you the folk of the Earth in pay,
With bars of gold your ramparts lay,
Bedeck the ocean with bow on bow,
Ye reckon well, but not well enough now.

French and Russian, they matter not,
A blow for a blow, a shot for a shot,
We fight the battle with bronze and steel,
And the time that is coming Peace will seal.

You, we will hate with a lasting hate, 
We will never forego our hate,
Hate by water and hate by land,
Hate of the head and hate of the hand,
Hate of the hammer and hate of the crown,
Hate of 70 million pressing down.

We love as one, we hate as one,
We have one foe and one alone—ENGLAND!

Stefan Zweig: The World of Yesterday  <https://www.amazon.com/dp/B0C7MR3M6P> wrote:

To my mind, the most typical and most moving case of such honest and at once inane ecstasy [at the start of WWI] was that of Ernst Lissauer.

I knew him well. He wrote short, incisive, brittle poems, and was the most kindly person imaginable… a round little man, a jolly face above a double double-chin, bubbling over with self-importance and exuberance, stuttering in his haste, and so possessed with poetry that nothing could keep him from citing and reciting his verses again and again… warm-hearted, comradely, honest…. 

When the war broke out, his first act was to hurry to the barracks to enlist…. He was promptly rejected. Lissauer was in despair but… wished to serve Germany with his muse. Everything that the newspapers and the German army communiqués published was gospel truth to him. His country had been attacked, and the worst criminal—as cast by Wilhelmstrasse—was that perfidious Sir Edward Grey, the British Foreign Minister. 

This feeling, that England was the arch enemy of Germany and responsible for the war, found expression in his “Hymn of Hate”… that in hard, short, impressive stanzas raised the hatred against England to an eternal oath never to forgive her for her “crime.” It was soon fatefully apparent how easy it is to work hatred…. The poem exploded like a bomb in a munitions depot. Possibly no other poem in Germany, not even the “Watch on the Rhine,” got around as quickly as this notorious “Hymn of Hate”…

No sooner had the war ended, with merchants seeking to resume trade and politicians making honest efforts towards mutual understanding… poor “Hate-Lissauer” was pilloried as the sole culprit of this insane hysteria… which in fact everyone from the highest to the lowest had shared in 1914…. Finally he was driven out by Hitler from the Germany to which he had been attached with every fiber of his heart, to die forgotten, the tragic victim of the one poem which had raised him so highly only to dash him to the lowest depths…

And:

In Vienna [at the start of August, 1914] I found the entire city in a tumult. The first shock at the news of war—the war that no one, people or government, had wanted—the war which had slipped, much against their will, out of the clumsy hands of the diplomats who had been bluffing and toying with it, had suddenly been transformed into enthusiasm…. There was a majestic, rapturous, and even seductive something in this first outbreak of the people from which one could escape only with difficulty…. Thousands and hundreds of thousands felt what they should have felt in peace time, that they belonged together. A city of two million, a country of nearly fifty million… each one was called upon to cast his infinitesimal self into the glowing mass, there to be purified of all selfishness. All differences of class, rank, and language were flooded over at that moment by the rushing feeling of fraternity. Strangers spoke to one another in the streets, people who had avoided each other for years shook hands, everywhere one saw excited faces. Each individual experienced an exaltation of his ego, he was no longer the isolated person of former times, he had been incorporated into the mass, he was part of the people, and his person, his hitherto unnoticed person, had been given meaning….

So deeply, so quickly did the tide break over humanity that, foaming over the surface, it churned up the depths…. Powers of darkness had their share in the wild frenzy into which everything was thrown—self-sacrifice and alcohol, the spirit of adventure and the spirit of pure faith, the old magic of flags and patriotic slogans, that mysterious frenzy of the millions which can hardly be described in words, but which, for the moment, gave a wild and almost rapturous impetus to the greatest crime of our time….

That I myself did not succumb to this sudden rapture of patriotism was not due to any unusual sobriety or discernment on my part, but rather because of my former manner of life. Two days earlier I had still been in “enemy” country and could convince myself that the great masses in Belgium were just as peaceful and unaware as our own people. What is more, I had lived too internationally to be able suddenly, overnight, to hate a world that was as much mine as my fatherland. I had long been dubious of politics, and especially during recent years I had discussed countless times with my French and Italian friends the stupidity of a possible war. I was inoculated to some extent against the infection of patriotic enthusiasm and, being thus prepared against this fever of the first hours, I remained fully determined not to allow this war of brothers, brought about by clumsy diplomats and brutal munitions-manufacturers, to affect my conviction of the necessity of European unity. As a result, I was inwardly secure from the very beginning of my world citizenship…