Hasson, a former deputy Shin Bet chief, is considered a highly esteemed Knesset member, but differences of opinion have emerged between him and his party chairman, Avigdor Lieberman. He will compete for a place on Kadima's list for the 18th Knesset in the party's primary elections.
"I went into politics in order to serve the State, and I'll do it in any framework in which I can be truly involved in the decision making and the shaping of policies, and in any place where I can contribute from my diplomatic and security-related experience," Hasson said Thursday morning.
"Just like the voter is entrusted with the duty of deciding on the way he sees fit from time to time, so is the elected person, and the elected person's responsibility is to the State of Israel, the electorate and his principles. And this is my decision."
Joining Kadima. Hasson with Livni (Photo: Yaron Brener)
Livni said during her meeting with Hasson, "We have known each other for a long time and have had long talks on issues which are on the State of Israel's agenda. Kadima represents the ideology of the Center, the advancement of a diplomatic process aimed at reaching Israel's national, security-related and strategic interests.
"The other way presented to the public represents no process and will lead to a complete stalemate and international pressure, which will impose initiatives and plans on Israel. These elections are about people and about the way Israel will take, and thus I believe we will be joined by people who can contribute to our way and who aspire to this perception."
Hasson participated in the negotiations on the Taba agreement, the Hebron Accord, the Wye River Memorandum and the Camp David talks, was one of the people who signed the Nusseibeh/Ayalon Initiative (also known as "The Peoples' Voice") for setting the outlines of the permanent agreement between Israel and the Palestinian Authority, and was the personal emissary of several Israeli prime ministers to Arab world leaders.
In the 17th Knesset he was one of the leaders of the battle against draft dodging and the initiator of a law stating that the State must fund the trips abroad of families of Israel's missing and kidnapped soldiers.
He served as head of the Knesset's Economics Committee and was a member of the Foreign Affairs and Defense Committee and the Intelligence and Secret Services Subcommittee.
Likud: He was always a leftist
MK Gilad Erdan (Likud) said in response to Hasson's decision, "Israel Hasson is a worthy person, but one must remember that he was always a leftist who was a member of public groups supporting the division of Jerusalem and handing it over to the Palestinians.
"The fact that he is joining Kadima proves once again that it is clearly a left-wing party."
Since the Knesset declared that the general elections would be held on February 10, former Minister Benny Begin and former IDF Spokeswoman Miri Regev announced that they would run in the Likud primaries, and former IDF Spokesman Nachman Shai said he would run in the Kadima primaries.
Amnon Meranda contributed to this report