If Israel intended genocide for Gaza, it would already be a city of insects and grass. You're engaging in the blood libel of invention of intention and need to go to the wikipedia page of Rafael Lemkin, the Polish Jewish lawyer-survivor who invented the term and the concept.

Since I had two Arab prime ministers as clients in my advertising business from 1996-2004 (the Sheraton Doha where Hamas' jihadi kleptocrats live and the Royal Meridien Bahrain), I'm hardly anti-Arab. I'm just an anti theocracy liberal secularist who disagrees with FGM, death for apostasy, extra-marital sex and adultery, pushing gays off rooftops and other homophobia, child marriage through the sale of poor 12 year old girls to older men, holy book literalism, whether Christian, Muslim or Jewish, gender inequality, teaching children anti-science religious fundamentalism, and authoritarian collectivism in all its forms.

Read Bernard Lewis' What Went Wrong: the Clash Between Islam and Modernity in the Middle East and David Pryce-Jones' The Closed Circle about Arabs' collectivist shame and honor culture to understand the source of their failure to modernize and prosper. The source of the Muslim world's failures is in the mirror they refuse to look at. Or read Algerian novelist Kamel Daoud's The Sexual Misery of the Arab World to understand how Muslims' war of dhimmitude supremacy restoration against Israel is a self-medicating gendered war of male supremacy restoration.

Hamas' jihadi human shield war in Gaza and the civilian deaths, which are at a far lower ratio to combatants than the 2016 siege of Mosul, would end tomorrow if Hamas returned the hostages and surrendered.

Here's who's responsible for civilian deaths: Hamas leaders like Abu Marzouk who said the tunnels are to protect the fighters, not civilians. He also said the aid is for the fighters, not civilians and that any attempt by civilians to take the aid will be met with full force. https://medium.com/illumination/not-anti-semites-just-anti-zionist-c933d146da12

You want "proportionate response" to Hamas' gleeful and ecstatic GoPro-ed orgy of rape, murder, torture, genital mutilation and beheadings. Here's what it would look like:

Now we can move on to #2, what “proportionate response” would really look like by imagining a counterfactual:

Jewish refugees’ 1988 genocidal charter demanding the destruction of the Arab state and its people,

Jewish refugee militants launching more than 7000 rockets against the target in a single week,

Its funding and supply of weapons by a co-religionist regional superpower with nuclear ambitions,

Its media and rabbis’ constant invocation of the Torah’s defining their enemies as “the satanic sons of pigs and dogs.”

A realistic role reversal would include the truly proportionate response that anti-Israel protesters and politicians demand:

“Every Friday and Saturday, every rabbi in Israel would remind his congregation how important it is to kill all of the Muslims in the world, wherever they find them.

“Israeli schools would brainwash Israeli kids to die killing Muslims, for the glory of making Judaism dominant in the Middle East. Israeli TV would broadcast threats of genocide to the Palestinians, with the IDF entertainment unit singing specially-written songs in Arabic about how bloody and glorious the massacre will be. (At the same time, they’d go to the UN and accuse the Palestinians of genocide.)

“Israeli girls would be killed by their own families if they liked boys. So would Israeli boys. IDF artillery would shoot rockets into Arab towns without any military targets, with the intention of killing as many civilians as possible, several times a day, sometimes hundreds of times a day.

“The Mossad would send young Jews to blow themselves up in shopping centres, hotels, cafes, nightclubs and bus stops around the world. Israeli municipalities would name streets after the suicide bombers, and the government would pay their families a pension for life in a scaled up “pay to slay” welfare scheme.

“The proud Jewish mothers of the suicide bombers would appear on Israeli TV encouraging mothers everywhere to give up their children for the cause of killing Muslims.”