There are words with meanings corrosive as acid. Heavy with the stench of historic crimes. Words that damn those who use them. One such word is "Judenrein", the Nazi-era word that means "cleansed of Jews". It is a surprise, then, to learn that it is a word that has been appropriated by Binyamin Netanyahu to describe the Palestinian demand for the dismantling of the Israeli settlements in the occupied West Bank. More shocking still, according to reports yesterday, it was used in talks between Netanyahu and Germany's Frank-Walter Steinmeier, foreign minister of a country still haunted by the guilt of its Nazi past – who was compelled to nod in embarrassed silence.

Netanyahu has not been alone in using "Judenrein" in recent months to describe the prospect of the removal of Israeli settlements in a future peace deal to create a Palestinian state .

As frustration among Israeli rightists has been mounting against the new policies of President Obama, the word has been creeping into the discourse, first in the rightwing blogosphere and now penetrating the mainstream media in Israel.

It is not the word "Judenfrei" – equally offensive – that Netanyahu used but its even stronger and more despicable companion. A word, under the Nazi race laws, that meant all trace of Jewish ancestry had been removed. The justification for its employment has been somewhat historically self-serving, arguing two things.

First, it contends that because Jewish communities historically lived on the West Bank and in Jerusalem before 1967 (over 3,000 years except for 19 years of Jordanian occupation between 1948 and 1967, according to this argument) any insistence on the removal of the settlements would amount to a de facto ethnic cleansing.

Secondly it argues – as Jonathan Dahoah-Halevi did on 2 July in Yediot Ahronoth – that the international community has accepted an unequal proposition, "that the Palestinians should be allowed to establish a country based on the religion of the majority of its citizens" while denying that same right to Israel. By that logic, he concludes, "international politics will no longer have to deal with the 'Palestinian problem' but rather with the 'Jewish problem' in Palestine".

It is an argument born of desperation that is as stunning for its sophistry as it is for its denial of what the settlement programme post-1967 represented. For while it is true that Jewish communities existed on the West Bank before the six-day war, the settlement programme that followed the occupation is regarded by most international bodies as a serious violation of international law. That view is based on the interpretation of Article 49 of the Geneva Convention as well as a series of UN security council resolutions that have deemed aspects of the settlements to be illegal.

Indeed, according to a report acquired by the Peace Now group in 2006, which it claimed it had acquired from the Israeli government's civil administration, as much as 32% of the land on which settlements are built is, in reality, privately owned by Palestinians.

The reality is that this is not about truth or the justness of Israel's historical argument for the existence of communities in territories it calls by the biblical names of Judea and Samaria. The evocation of Judenrein by Netanyahu and by other commentators is the most cynical of ploys in a negotiation that his government feels that is going against it. Under pressure from Obama to freeze settlement building completely – including the construction that Israel likes to label as "natural growth" – it is being forced into ever more extreme language to defend the continued existence of the settlers in the occupied Palestinian territories in language, like that used with Steinmeier, to embarrass and cajole.

There are words with particular meanings. Bloody with the worst offences. To use "Judenrein" so cheaply to score a political point dishonours the memory of history and its victims. It shames Israel's prime minister.

The Secret Life of War: Journeys Through Modern Conflict by Peter Beaumont is published by Harvill Secker