In a controversial poem titled "What Must Be Said" which was published in Germany's Suddeutsche Zeitung newspaper on Wednesday, Grass expressed concern over the consequences of Israel’s plan to attack Iran.
“Why do I say only now ... that the nuclear power Israel endangers an already fragile world peace? Because that must be said which may already be too late to say tomorrow," Grass wrote.
"We could be suppliers to a crime that can be foreseen, which is why none of the usual excuses would erase it," Grass writes, referring to Germany’s plan to sell Israel a sixth nuclear-capable Dolphin-class submarine that can carry nuclear warheads.
"I will be silent no longer, because I am weary of the West's hypocrisy,” Grass added.
Three earlier-model Dolphin submarines had been delivered to Israel between 1998 and 2000. In 2006, Tel Aviv placed its fourth and fifth orders for two more advanced subs.
The fourth one is scheduled for delivery by 2013. The fifth and the sixth orders are due for delivery in 2014 and 2016 respectively.
Israel is the only possessor of nuclear weapons in the Middle East and it has never allowed inspections of its nuclear facilities nor has it joined the Non-Proliferation Treaty (NPT) based on its policy of nuclear ambiguity.
According to a survey conducted in 2011 by the Berlin-based Friedrich Ebert Foundation, more than 50 percent of the European people believe Israel is the most serious threat to global security.