Upon returning from his journey to Europe, Prime Minister Benjamin Netanyahu has a task of national importance to carry out - getting rid of Foreign Minister Avigdor Lieberman. The damage that Lieberman is causing the country and its relations with foreign countries is getting worse, and it is similar to the farce of Amir Peretz at the Defense Ministry. Netanyahu must get a hold of himself and put an end to this.

During the hot August days, usually thin on news, Lieberman is giving the media and MKs thirsty for comments a daily show. He is bashing Sweden, thumping Norway, clearing the Foreign Ministry of Arabs and Haredim, making the prime minister out to be a fool and wasting his time in a pointless diplomatic effort - threatening his envoys to align themselves with the official line being dictated from above or wind up on the outside. Who knows what he will announce next.

There is no doubt that Lieberman is a gifted copywriter who understands the media well. He is entitled to have his right-wing views and to think that the peace process is a dangerous folly. He is also justified in his claims that he is loyal to his pre-election campaign slogans, which led Yisrael Beiteinu to 15 seats in the Knesset.

Whoever thought his appointment to the foreign ministry would soften up the scrappy, aggressive Yvet, granting him diplomatic finesse, was proven wrong. Lieberman has not changed nor does he intend to change.

But the problem is not Lieberman's freedom of expression, which is not in question, but his conduct as foreign minister. It can be summed up as an utter failure. Foreign ministers have a dual role: furthering national interests through diplomatic exchanges with other countries, and representing the views of the international community in the domestic decision-making process. In the room where they decide war and peace, the foreign minister must sound like a statesman, just as a defense minister must present the military possibilities.

Lieberman is finding it difficult to fulfill his role for a simple reason: the boycott and isolation that the world has imposed on him. Egypt is not forgiving him for insulting its president, and in its footsteps other Arab countries are ignoring Lieberman. The Europeans and the Americas who met with him had no choice but to do so, and made their sentiments toward him clear by downplaying the meetings. French President Nicolas Sarkozy even called on Netanyahu to replace Lieberman.

The Russians, whom Lieberman thought of grooming as allies, invited him to Moscow at the same time they met with Hamas politburo chief Khaled Meshal.

Under such circumstances, the foreign minister is neutralized. In the absence of interlocutors he cannot deal in diplomacy. His visits to South America and Africa, in spite of their importance, deal with issues that are peripheral to Israeli foreign affairs. Thus his ability to contribute to the strategic decision making in Jerusalem is narrowed.

What will he present in discussions? His notes on the beaches of Brazil? The result is that the internal balance at the top is undermined. The leaks from the meetings of the forum of six ministers which have Lieberman talking sensibly and not saying wild things only make the situation more ridiculous. After all, what did they expect? That he would be swearing in Russian while waving a bat?

Ironically, the foreign minister is not even trying to improve his conduct, but is ignoring the few tasks that he has left. He refuses to take part in the peace process, which he thinks is unnecessary, either arguing that he has "a conflict of interest because he is a settler" or by claiming that he does not believe in it.

His predecessors fought their prime ministers in order to get a piece of the main work of Israeli diplomacy, while he is giving up on it from the start. The alternative that he found is to deal with primitive forms of public relations, centered around the worn-out claim that the Europeans are anti-Semites and former Nazi collaborators, and therefore they have no ethical footing for judging Israel's actions.

Where has this gotten him? Has Israel benefited a bit more in terms of international support? Or are its enemies just laughing and raking up points at its expense?

There are expectations on the domestic political front that the attorney general will soon press charges against Lieberman in line with police recommendations and will bring an end to his damaging tenure.

But Netanyahu should not hide behind Attorney General Menachem Mazuz. As the most experienced diplomat in government, Netanyahu knows all too well the damage that Lieberman is causing at the Foreign Ministry.

Right before the peace process is resumed and the Iranian issue comes to a head, he must immediately replace Lieberman with a more appropriate foreign minister, irrespective of the criminal investigation against the current one. It is by this that the prime minister's leadership will be tested.