A great deal of heat has been caused by a letter sent last month by Israel's Foreign Minister, Avigdor Lieberman, to the Quartet (the USA, EU, UN and Russia) - the group charged with facilitating a Middle East peace process.

In the letter, addressed to the EU's Baroness Ashton, Lieberman called on the Quartet to encourage new elections in the Palestinian Authority in the hope that these might result in the removal of Palestinian president, Mahmoud Abbas, whom Lieberman castigated as interested only in "encouraging a culture of hatred".

When the letter became public, Lieberman was accused of interfering in the internal affairs of another country and of encouraging "regime change". Such was the international fury that Prime Minister Netanyahu felt compelled to issue a disingenuous communiqué distancing his government from the comments, and insisting that they did not "represent the position of the Prime Minister or that of the government".

First, I wish to ask why it was leaked. The second question (closely related to the first) is: who was the leaker? In this case, we know that the letter fell, mysteriously but conveniently, into the hands of Ha'aretz, a paper fiercely critical of the Netanyahu administration in general and of its uncompromising foreign minister in particular.

Its publication may best be viewed as an attempt by Ha'aretz and the Quartet to embarrass Netanyahu's government, fuel dissension within it, and cause Lieberman to be isolated, disowned and even (who knows?) dismissed. There is of course an amusing irony here, because this might be uncharitably viewed as an attempt by the Quartet to interfere in the internal affairs of another country - but let's be charitable and not pursue this, at least for this week.

Palestinian streets are named after terrorists or murderers

So what did Lieberman actually say in his letter? He began by observing that Israel had "undertaken several significant gestures towards the Palestinians" - including an advance of tax receipts amounting to around £28 million. What - he asked - had been the Palestinian response? "We encountered repeated Palestinian patterns of refusal and consistent attempts to turn to pointless activity, counterproductive to any constructive efforts."

Lieberman then accused Abbas of "damaging behaviour towards Israel, including extreme cases of encouraging a culture of hatred, praising terrorists, encouraging sanctions and boycotts, and calling into question the legitimacy of the existence of the state." The PA, he observed, "is a despotic government riddled with corruption… Due to Abbas' weak standing, and his policy of not renewing the [peace] negotiations… the time has come to consider a creative solution, to think 'outside the box', in order to strengthen the Palestinian leadership." And so he called for "a new, legitimate, hopefully realistic Palestinian leadership" to be elected."

I fail to see in these remarks anything other than the bleak, unvarnished truth. Abbas has squirmed and wriggled and failed to return to the negotiating table. His government has raised objection after objection, and precondition after precondition. But it has not sat down with its Israeli counterpart to hammer out a lasting peace deal. Instead, Abbas and his colleagues have indeed - as Lieberman pointed out - engaged in a sustained campaign of vilification against the Jewish state and even the right of Jews to have one.

Scarcely 24 hours after the letter had been delivered, Abbas made a public statement referencing "the alleged Jewish Temple" in Jerusalem. Palestinian streets are wantonly named after terrorists and murderers, whose exploits are officially celebrated. Jewish holy sites - such as the tomb of Joseph in Nablus - have been deliberately desecrated.

But what really seems to have aroused the ire of the Quartet and of Ha'aretz is Lieberman's indelicate but necessary reference to the fact that Abbas's tenure of the Palestinian presidency lacks any legitimacy. His term of office actually ended on January 9 2009. An election was supposed to have been held in July 2010, but never took place. Dates in May and June 2012 have also come and gone.

To point this out is not interfering in the internal affairs of another country. It is merely stating the bleeding obvious.