The former Israeli Intelligence Minister called for negotiations with Hamas in an interview with CNN on Tuesday.

"Hamas is a very bad option, undoubtedly. But there are worse options than Hamas," Efraim Halevy, former Mossad chief, said.

"And we already know what some of them might be, especially one of them: the ISIS - which is operating now in the northern Iraq and central Iraq - has its tentacles in the Gaza Strip too."

Halevy said that just as in Europe, ISIS is recruiting in Gaza.

It is "inconvenient politically," Halevy said, for both Israel and Hamas to admit that they negotiate. But the truth, he said, is that they have already been doing it for years.

"We have coined a new method of diplomacy in the twenty-first century: we don't meet with them, we don't talk to them, but we listen to them. Each one listens to the other side. Somehow in the end an understanding is crafted."

"We have had several rounds with Hamas in recent years, and the previous rounds ended up in agreements … arrangements, as it was called - 'arrangements,' not even agreements."

"But in effect it was a negotiation between us and Hamas. When you had the deal on the kidnapped soldier Shalit, we negotiated with Hamas."

"The Prime Minister wants to lead Hamas into a position where they will accept the cease-fire," Halevy said.

"I do not detect for the moment any great appetite on the part of the Prime Minister to go at least in the immediate future into anything beyond air attacks and maybe here or there a ground skirmish."

Prime Minister Netanyahu, he said, wants to leave a "cowed Hamas, a weakened Hamas" in power in Gaza.

"Israel has no appetite to take over responsibility for the population in Gaza."