Israel's Mossad killed a Palestinian wanted for airplane hijackings by feeding him poisoned Belgian chocolate over six months in the late 1970s, according to a new book, the author said Saturday. The book, "Striking Back," is apparently the first time that details of the killing have come to light and provides a glimpse at how sophisticated Israel is at poisoning. In his book, author Aaron Klein describes how Israel tracked down Wadia Haddad, an operative of the Popular Front for the Liberation of Palestine, in Baghdad. Haddad had gone into hiding in the Iraqi capital after Israel began killing Palestinian militants around the world, Klein told Israel Radio. Suspected in multiple hijackings, including the 1976 takeover of an Air France airplane in Entebbe, Uganda, Haddad knew from the Israeli tactics that he could be shot or bombed as he walked the street or when picking up a phone. Haddad was cautious of his every move, avoiding travel outside of Iraq, said Klein, a Time magazine correspondent in Jerusalem. But the 140-kilogram (309 pounds) food lover had a weakness: chocolate. In Baghdad of 1977, luxuries like fine chocolates were rare. Through a Palestinian working with the Mossad who had gotten close to Haddad, the agency was able to feed Haddad chocolate brought from Belgium and spread with poison over six months, Klein said. Haddad died in March 1978, showing only symptoms of leukemia but no signs of poisoning, Klein told the radio. "This elimination was very successful because, as soon as this person was taken out and stopped working, in effect all the terrorist activity, especially the hijacking of airplanes, ceased altogether," Klein said. The Mossad's ability to poison has improved drastically over the years, Klein said. In 1997, Israeli agents in Jordan injected Hamas leader Khaled Mashaal with a poison that would have killed him within 24 hours. But the plot was discovered, and Jordan forced Israel to provide an antidote quickly enough to save Mashaal. Since the death of Yasser Arafat in late 2004, rumors have swirled in the Arab world that the longtime Palestinian leader was poisoned by Israel. Klein said there is no evidence that Israel killed Arafat, but that it would take years to prove that poisoning took place because of Israel's sophistication. Arafat died in a Paris hospital in 2004 of a massive stroke that followed a sudden deterioration in his health. Medical records have been inconclusive about the cause of death, leading some Palestinians to implicate Israel. Klein's book recently came out in Hebrew in Israel. Previously, it had been translated from English into several other languages.