As Israel's war on the Gaza Strip continues amid Hamas rocket fire into Israel—a conflict that has, this time around, cost the lives of at least 560 (largely civilian) Palestinians and 27 Israelis—and swells into the present ground invasion, it bears mentioning that the current conflict between Israel and Hamas is deeply personal—for the leaders on each side.

Before Benjamin Netanyahu tried to cripple Hamas, he, in fact, attempted to assassinate its leader. But in botching the operation, the Mossad created bitter enmity between the two men at the center of the conflict.

The year was 1997; the place was Amman, Jordan. Israel had identified the little-known Hamas operative Khalid Mishal, then 41, as a likely future leader of the movement.

When Netanyahu, then in his first term as prime minister, called for a list of Hamas targets to avenge a series of suicide bombings in Jerusalem, he is said to have personally placed the bull’s-eye on Mishal, overruling intelligence advice that a more high-profile Hamas operative should be taken out.

The plan was absurdly complicated. Instead of the clean snatch or sniper shot at which the Mossad excelled, it called for an Israeli agent to sidle past Mishal as he arrived for work at his Amman office. That agent was to create a kerfuffle by popping a pre-shaken can of soda while an accomplice would amble past in the opposite direction, using a special device to deposit a slow-acting killer drug in the distracted Mishal’s ear.

The idea was that Mishal would go about the rest of his day and would respond to a feeling of tiredness by taking a nap—from which he would never awake. The drug was a powerful derivative of the surgical painkiller fentanyl, which the Israelis expected would dissipate so quickly in Mishal’s body that there would be no trace of it by the time a postmortem was done.

The plot succeeded as spectacularly as it failed. The poison was in Mishal’s ear, but his two bodyguards witnessed the attack and one of them gave chase, capturing the two Mossad men after all three engaged in bloody hand-to-hand combat.

Their capture forced Netanyahu to fess up to a furious King Hussein of Jordan.

The monarch had gone out on a limb, signing a peace treaty with Israel against the wishes of his people; and he was exceptionally irritated by Netanyahu’s behavior as prime minister. Now the Israeli leader’s resort to cloak-and-dagger games in the streets of the Jordanian capital had presented him with the exquisite pleasure, for an Arab leader dealing with his Israeli counterpart, of having two Israeli prisoners to barter for an outcome that would humiliate Israel.

The poison did its job—within hours Mishal was at death’s door. Warning that if Mishal died, the Mossad duo would be hanged, the king called in the big guns—then U.S. president Bill Clinton and his Middle East team. Hussein’s two demands were extraordinary: he required the Israelis to cough up a vial of the antidote to the poison, the only means of saving Mishal’s life; he insisted that Netanyahu order the immediate release, from Israeli prisons, of a number of Palestinian prisoners, including the ailing Sheik Ahmed Yassin, the wheelchair-confined founder and spiritual leader of Hamas who was one of Israel’s most notable Palestinians in their custody.

The big names in the Clinton White House were involved—Sandy Berger, Dennis Ross, and Bruce Riedel. But in researching a book on the crisis and its impact on the Hamas leadership, I was told that this was one of those rare occasions when none of the president’s men would support Netanyahu—he was told there could be no face-saving, he would have to deliver on both of King Hussein’s demands.