In Britain or the United States, poets opine and some of the people may listen – and then usually they move on.
The chattering class might chatter a little louder, but the great sweep of politics is rarely changed.
But in Germany, artists are taken very seriously and few more than Guenter Grass.
It is not just his Nobel Prize, but the way his novels reflected Germany’s Nazi past with brutal clarity. They were like mirrors that revealed the true face to those brave enough to look at themselves.
That’s why the Swedish Academy gave him the Nobel Prize, citing his courage in “recalling the disavowed and the forgotten: the victims, losers and lies that people wanted to forget because they had once believed in them”.
In the years after the war, Guenter Grass’s writing gave him a status of Conscience of the Nation, and in a nation which takes its soul-searching very seriously indeed, particularly because the Holocaust and the other crimes of the Nazis provided so much material through which to search.
For more than 60 years after the war, he showed a zeal and what seemed like a searing honesty in the way he berated those who refused to admit their own dark pasts.
But this reputation was dented when it emerged in 2006 that he had kept quiet about his own past as a member of the Waffen-SS (a branch of the military under the direct control of the Nazi party).
Even then, he was not universally discredited. Some took this as evidence of the complexity of the psyche of the man (and by implication of the nation).
With this background, the poem “What Must be Said” was never going to be a passing work of whimsy, filling space on the arts pages but not troubling the rest of the newspaper.
It is a poem which concentrates on Israeli nuclear weapons as the prime danger in the Middle East.
Iran is mentioned (“subjugated by a loud-mouth”, as the poem says). But it is Israel which is the focus (“It is the alleged right to the first strike that could annihilate the Iranian people”).
And he criticises Germany for selling submarines to Israel which could be used in this “first strike”.
It is this one-sided concentration which has brought the fiercest criticism within Germany.
The chairman of the German parliament’s foreign affairs committee, Ruprecht Polenz, said that Grass “has difficulties whenever he comments on politics and is often wrong”.
Foreign Minister Guido Westerwelle said: “Putting Israel and Iran on the same moral level is not ingenious but absurd”.
The truly biting criticism is that Guenter Grass is displaying a sophisticated anti-Semitism.
On this argument, his fault is not that he criticises Israeli government policy but that he criticises it especially hard without doing the same to others (like Iran).
This alleged one-sidedness amounts, according to Henryk Broder of Die Welt, to “educated anti-Semitism”.
The literary critic, Marcel Reich-Ranicki, who survived the Holocaust, called the poem “disgusting”, adding, “Iran wants to wipe out Israel, and Guenter Grass is versifying the opposite”.
After the poem’s publication, Guenter Grass went on television and defended himself.
“I expected dissent,” he said “particularly because the fact that Israel is a nuclear power is still treated as a taboo”.
But: “I didn’t expect the reactions to be directed at my person rather than my arguments, and I didn’t expect them to be so insulting and venomous, culminating in the accusation of anti-Semitism. Such a massive condemnation, to be pilloried in such a way – that is something I have never experienced before”.
One of the accusations against the writer is that he cites Israel as the likely first striker in a nuclear conflict.
He replied to this: “Excuse me, if you attack a nuclear plant with conventional missiles you run the risk of a nuclear catastrophe”.
All this matters very much in Germany as it wrestles with its own past – and so it matters in the rest of the world too, because Germany is an economic giant which is finding its feet.
In 2008, Chancellor Merkel addressed the Israeli parliament and declared that the security of Israel was central to German foreign policy.
It has been a given in Germany that it would stand shoulder-to-shoulder with Israel.
What Guenter Grass has done is to open up debate on that relationship.
Poems do matter, particularly this one, in Germany and in Israel.