A renowned German poet and Nobel laureate who criticized Israel's posession of nuclear weapons has been banned from entering the Jewish state, under a law used to block the entry of former Nazis.

In the poem What Must Be Said -- published last week in Germany's Sueddeutsche Zeitung -- Gunter Grass said Israel's atomic weapons endanger world peace.

Grass also wrote of Germany's collective reluctance to criticize Israel, rebuking his own silence on the matter, before acknowledging he would himself face inevitable accusations of anti-Semitism.

On Monday the 84-year-old, who served time as a young man in the Waffen SS during World War II, was labeled a persona non grata by Israel's Interior minister Eli Yishai for his attempt to fan the flames of hatred against the state of Israel and its people, and thus to advance the idea to which he publicly affiliated in his past donning of the SS uniform.

On Thursday, Prime Minister Benjamin Netanyahu also slammed Grass for his shameful comparison between Israel and Iran, which says very little about Israel but speaks volumes about Mr. Grass.

Israel's reaction has drawn criticism in Germany, with several high-profile politicians labeling the move excessive.

The reactions of the Israeli government (...) I consider to be excessive and significantly more likely to harm Israel internationally. Ruprecht Polenz, a Christian Democrat politician and chairman of the Foreign Affairs Committee of the lower house of the federal parliament, told the Sueddeutsche Zeitung.

Referencing Grass' assertion in the poem that he would likely face accusations of anti-Semitism, former Minister of State at the Foreign Office Gernot Erler added: The travel ban unintentionally confirmed the taboo thesis of Grass.

In response Grass has said he wished he had made it clear he was attacking the Netanyahu government and not Israel as a whole.

What Must Be Said, By Gunter Grass (Translation Provided by The Guardian)

But why have I kept silent till now?

Because I thought my own origins,

Tarnished by a stain that can never be removed,

meant I could not expect Israel, a land

to which I am, and always will be, attached,

to accept this open declaration of the truth.

Why only now, grown old,

and with what ink remains, do I say:

Israel's atomic power endangers

an already fragile world peace?

Because what must be said

may be too late tomorrow;

and because - burdened enough as Germans -

we may be providing material for a crime

that is foreseeable, so that our complicity

wil not be expunged by any

of the usual excuses.

And granted: I've broken my silence

because I'm sick of the West's hypocrisy;

and I hope too that many may be freed

from their silence, may demand

that those responsible for the open danger we face renounce the use of force,

may insist that the governments of

both Iran and Israel allow an international authority

free and open inspection of

the nuclear potential and capability of both.