Benjamin Netanyahu's comeback campaign focused on the Iranian threat. "The year is 1938 and Iran is Germany," he warned as head of the opposition. "When [Iranian President] Mahmoud Ahmadinejad denies the Holocaust, he is preparing a second holocaust against the Jewish people. Believe him and stop him."

Netanyahu did not content himself with warnings, and called for putting Ahmadinejad on trial in The Hague on charges of incitement to genocide. He and other supporters collected threatening utterances from the Iranian president against Israel, determined they violated the international Convention on the Prevention and Punishment of the Crime of Genocide, and set out to enlist support in the West.

"In 1938 Hitler did not say he wanted to destroy. Here Ahmadinejad is saying clearly that this is his intention and we are not even crying out. At least say a crime against humanity. It is necessary to put this issue right in the world's face, that here is a matter of a program for genocide," said Netanyahu four years ago.

Jewish organizations held show trials, American congressmen and British members of parliament expressed support and jurists fired off letters. "Had the world listened to Hitler's words and watched his actions, the Holocaust could have been prevented," wrote Los Angeles lawyer Baruch Cohen on his blog American Trial Attorneys in Defense of Israel, in an open letter to United Nations Secretary-General Ban Ki-moon.

Ahmadinejad did not take fright. He kept on with his hate speeches, threats and Holocaust denial; he traveled the world unperturbed and the Iranian nuclear program moved forward.

In Israel, however, a change occurred and Netanyahu moved from the television screens to the Prime Minister's Office. Now he was given a mandate to act and not just talk against the Iranian threat.

Three weeks from now, Netanyahu will have a one-time opportunity to stop the new Hitler and thwart the incitement to genocide. Ahmadinejad will pay his first visit to Lebanon and devote an entire day to a tour of the southern part of that country. He will visit sites where Hezbollah waged battles against Israel and, according to one report, he will also pop over to Fatima Gate, just beyond the border fence at Metula. The route is known, the range is close and it is possible to send a detail across the border to seize the president of Iran and bring him to trial in Israel as an inciter to genocide and Holocaust denier.

The media effect will be dramatic: Ahmadinejad in a glass cage in Jerusalem, with the simultaneous translation earphones, facing grim Israeli judges. In the spirit of the times, it will also be possible to have foreign observers join them (David Trimble of the Turkel commission was a leader of the "try the Iranian president" initiative ).

There are also operational advantages: Iran will hesitate to react to its president's arrest by flinging missiles, out of fear for their leader's life. It will also be possible to capture Hezbollah leader Hassan Nasrallah, who will no doubt emerge from his hiding place and accompany Ahmadinejad. Israel will have high-ranking hostages it will be able to exchange for Gilad Shalit.

And if the world has any complaints, it will be reminded that the Americans invaded Panama in order to arrest its ruler Manuel Noriega - and only for dealing drugs, a far smaller offense than incitement to genocide.

Of course, the idea also has disadvantages. Ahmadinejad might be killed in the action and Iran would embark on a cruel war of revenge. The precedent of arresting leaders would endanger Israeli personages suspected abroad of crimes against humanity or murder (according to the Goldstone report and the flotilla report ). Ahmadinejad could be acquitted and make Israel look like a bully and Netanyahu a fool.

Nevertheless, how can Netanyahu refrain from an action to stop Hitler's heir, when the year is already 1939, if not 1940? According to Netanyahu's reasoning, if he refrains from acting history will condemn him for "not preventing a crime," as with Margalit Har-Shefi, who didn't stop Yigal Amir from assassinating Yitzhak Rabin.

This, of course, is not going to happen. The risks are too great and the intention here is not to give operational advice but rather to demonstrate the gap between those shouting from the opposition and those in power, and between "public diplomacy" - Israel's latest official translation for the term hasbara, which is something between self-justification and propaganda - and statesmanship.

When you are talking and looking for messages to get yourself into prime time, you can say anything without taking risks. But when you are the prime minister, the constraints of reality become clear and the gap between talk and deeds is revealed. Therefore, it is best to be cautious in speech and to remember that not everything is hasbara, as even a media gimmick can come back to haunt you.

And perhaps I'm wrong. Could it be the elite special operations unit is training and Ahmadinejad and Nasrallah are on their way to secret detention facility 1391, to the cell that served the captives Sheikh Abdel Karim Obeid and Mustafa Dirani?