JTA — Gunter Grass, Germany’s Nobel Prize-winning author, has published another poem criticizing Israeli policy.

The poem also praises Mordechai Vanunu, who served 18 years in prison after being convicted in 1988 of treason and espionage for leaking Israel’s nuclear secrets to the British newspaper the Sunday Times of London.

The poem, called “A Hero in Our Time,” is part of a new book of Grass’ poems, “Eintagsfliegen,” released in Germany on Saturday.

In the poem, Grass calls Vanunu a “Modern-day hero” and writes that “heroes such as that are needed in the world, which utters words of peace while planning destruction.” The poem traces Vanunu’s life story.

Grass published poem in April in Germany’s Suddeutsche Zeitung newspaper and other international papers, claiming that Israel is endangering world peace by threatening Iran. The poem — titled “What Must Be Said” – also condemned the German government of Chancellor Angela Merkel for agreeing to subsidize the sale of additional submarines “from my country” to Israel “justified as reparations.”

Israel declared Grass a “persona non grata” following the publication of the poem.

In 2006, Grass admitted in an interview that he had joined the Waffen-SS as a teenager at the end of World War II, and was accused at the time of having hidden the truth for decades while at the same time pointing the finger at others for hiding their Nazi past.