A leading UK military analyst says Israel's declared war aim of destroying Hamas is not credible and that he sympathizes with Israeli hostage group campaigners who believe that an expansion of military action will endanger the lives of the remaining captives.

Retired Air Vice-Marshal Sean Bell told CGTN the only way to end the 22-month conflict is via "a political, negotiated settlement" and said his contacts within the Israeli Defense Forces insist that Prime Minister Benjamin Netanyahu's internal power struggle is behind the country's continued military campaign.

"Of the 251 hostages that were taken, 202 have been released, whether released live or dead, but they've only really come out through negotiation," said Bell. "There's 49 left, plus one who's been there for 11 years, and only 20 are believed alive. The only way to get those out historically has been through negotiation."

In a statement on a possible expansion of the military offensive in Gaza, The Hostage and Missing Families Forum in Israel said "Netanyahu is leading Israel and the hostages to doom."

According to Bell: "It doesn't look like there's any appetite at the moment from the Israeli government to do that and therefore further military action is likely to not secure the fate of those remaining hostages."

Bell, who served in The Gulf, Afghanistan and Bosnia among his tours with the British Royal Air Force, said Netanyahu's aim to destroy Hamas could not succeed.

He insisted: "Military action is a means to an end, it's not an end in itself. The end in itself is a political, negotiated settlement. If you gave me the task of wiping out Hamas, I'd look at you and say 'It's almost impossible to do that.' You can't destroy an ideology. What you have to do is drive it down so it's no longer a credible threat."

Open letter

Bell referred to Monday's publication of an open letter signed by hundreds of retired Israeli security officials, including former heads of intelligence agencies, demanding an end to the war in Gaza.

He declared: "We've seen a group of very distinguished senior Israelis who have said 'Hamas is no longer the threat, we have to transition to some sort of political settlement.' Because if you don't have an idea of what that looks like, this war will carry on in perpetuity."

Rules of conflict

Bell added: "I've got some colleagues who are in the Israeli Defense Forces and they, without being quoted, effectively say a lot of this is down to Netanyahu now, his own power struggle and the like.

"Hamas will not stop until a Palestinian state has been established. Most of the international community think that's the right answer. Prime Minister Netanyahu clearly doesn't believe that, and whilst there's that impasse this conflict will continue."

With ever-growing condemnation of the civilian toll in Gaza, Bell said long-standing rules of armed conflict "don't seem to be being followed" by Israel.

"I spent two years of my life, three tours, in Afghanistan and we were targeting some pretty high-value targets that time," he recalled. "The rules of armed conflict were very clear and many times the lawyers stopped us hitting people because there were civilians around them – we had to wait until they were isolated. Those rules don't seem to be being followed if you look at the destruction in Gaza."