That question, and thoughts on the nature of today's Jewish state, are on the minds of many Israelis as the anniversary of the November 4, 1995 assassination highlights the gulf between visionary hope and stark reality.
Tens of thousands of Israelis -- as many as 100,000 according to some media reports -- gathered late Saturday for a memorial rally in the Tel Aviv square where Rabin was shot dead and which now bears his name.
Rabin, who headed the victorious Israeli armed forces in the 1967 Six-Day War, as premier chose instead the path of peace, sharing the 1994 Nobel Prize with domestic rival Shimon Peres and Palestinian leader Yasser Arafat for their roles in forging the Oslo peace accords.
Twenty years after that time of euphoria for the Israeli peace camp, the mood at Rabin Square on Saturday was sombre.
Merav, 44, a regular at the annual event, said it was the largest turnout for years, but she also felt further than ever from the spirit of the murdered politician.
"I have not had hope since November 4, 1995. Our innocence was also killed on that evening," she said, agreeing with the many who say that the Oslo agreements died alongside Rabin.
"Rally of Despair" was the heading to a commentary on the event in the Israeli daily Maariv; "Rally to Nowhere" was the headline in the mass-circulation Yediot Aharonot.
Since the beginning of October, Israelis and Palestinians have been embroiled in a new wave of violence that has seen nine Israelis, 67 Palestinians and an Arab Israeli killed, raising fears of a new Palestinian uprising against Israeli occupation.
The two sides have not talked peace for more than 18 months.
TWO STATES CONCEPT 'DEAD'
Former US president and friend of Rabin Bill Clinton urged the Tel Aviv crowd on Saturday "to complete the final chapter in the story" of Rabin's quest for peace.
But as he spoke, Ofir Akunis, science minister in Prime Minister Benjamin Netanyahu's government, the most rightwing in Israeli history, was saying elsewhere that the idea of a Palestinian state alongside Israel "is dead", Maariv reported.
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Given this atmosphere, many people are asking: "What would have happened had Rabin not been killed?"
If he had lived to serve another term, "We would have reached a permanent agreement with the Palestinians and perhaps peace with Syria," Uri Savir, Israel's chief negotiator at talks leading to the Oslo Accords, told AFP.
After the assassination the left was defeated in a general election and Netanyahu was elected premier for the first time.
"He has worked to meticulously dismantle everything that was foreseen," Savir said.
"Do you think we have a magic wand? No. Must we always live by the sword? The answer is yes," Netanyahu was quoted as telling a parliamentary committee last month.
Some on the left doubt if Rabin would have been able to pursue his goals to their hoped for conclusion had he lived.
'A RESPECTABLE LEADER'
"If Rabin was alive he would be a retired but hyperactive nonagenarian like Peres," said Anshel Pfeffer, a columnist for the left-leaning Haaretz newspaper.
"Netanyahu would nonetheless be prime minister and would continue to explain why everything is the fault of the Palestinians."
Rabin's daughter, former MP Dalia Rabin, says that there was no real glue between her father and Arafat and that he could not have brought about lasting peace on his own.
"There is a feeling that a sort of relationship of trust was built between Arafat and Rabin, but it was, on the whole, very fragile," she said.
A poll published by the pro-Netanyahu freesheet Israel Hayom said that 76 percent of respondents considered Rabin "a respectable leader" and he was missed by 55 percent, but only a third approved of the Oslo Accords.
Palestinians also have mixed feelings about Rabin, recalling how as defence minister during the first Palestinian intifada that erupted in 1987 he called on soldiers to "break the bones" of rioters.
Arafat's successor, Palestinian president Mahmud Abbas, referred in a September speech at the United Nations to the "cancer" of Jewish settlement.
Today, for the Palestinian public, both its own leadership and Rabin are emblematic of the failure of the Oslo process.