The report, prepared by the State Comptroller, offered a strong indictment of Prime Minister Benjamin Netanyahu's government, claiming it had no strategic goals when the 50-day war started in early July 2014.
The strategic goals should have come first "as required in a proper decision making process," said the report. But it found that that those goals were only set after the Israeli military had put forward its operational plans.
According to the findings, decisions during the war were made by Netanyahu, then-Defense Minister Moshe Ya'alon, and then-IDF Chief of Staff Benny Gantz, while critical information was withheld from the Security Cabinet.
"Ministers were not presented with significant and necessary information for decision making," the report said.
The report also found that the country was not adequately prepared for the threat from Hamas-built tunnels leading from Gaza into Israel.
In a preemptive strike, Netanyahu blasted the report at a meeting of his government ministers on Monday, a day before the report's release. "There has never been a cabinet in the history of Israel that was more updated," said Netanyahu, "and when you enter the cabinet, you have to leave outside your cell phone, petty politics, and personal interests."
On Facebook, he said, the most important wartime decisions are not made in the open.
"The real, important lessons are not in the report, and we implement them with no declarations and statements to the media. We implement them thoroughly, consistently and quietly," Netanyahu wrote.
"Contrary to the Comptroller's report -- I back those heading the IDF, The ISA (Shabak) and the security system, who guarded and are guarding the citizens of the state of Israel.
Netanyahu added: "The soldiers and commanders fought, risking their lives -- and the people of Israel are proud of them."
Gantz, who led the IDF during the campaign, would not comment when his spokesperson was reached by CNN.
The findings were portrayed as a political stunt by former defense minister Ya'alon.
"Those who were busy with politics in the cabinet then, in an unprecedented way, will continue doing it this week too," Ya'alon said on Facebook.
"They will tell you they were not told, were not given reports and the biggest lie of all? That we were not prepared, that we lost. That's nonsense. There are those who leak and those who fight."
Meanwhile, Yair Lapid, an opposition lawmaker who has been polling nearly even with Netanyahu's Likud party, should snap elections be held, criticized the Prime Minister, accusing him of being incapable of admitting an error.
"What's worrying is not the mistakes, but the denial, the effort to deal with images and politics and media spins at the expense of national security. That's not the way to run a state. The Prime Minister engaged in a political struggle against members of his government, his cabinet and against undeniable facts, instead of admitting that he made a mistake," Lapid said in a statement on Facebook.
Defense Minister Avigdor Liberman implied the report was more about political retribution.
"All the statements of politicians in the past few days haven't dealt with drawing conclusions, but rather in settling the scores and exchanging accusations," Liberman, who served as Foreign minister during the war, said in a statement from his office.
Final part of report to be released soon
The report, released in four separate parts, covers Israel's actions before and after the Gaza war.
The first part, released in December examined Israel's preparation for the threat of missiles and rockets. The second and third parts, which make up some 350 pages and were release Tuesday, cover the decision-making process and the threat of the tunnels entering Israel from Gaza.
The final part, which is set to be released in the near future, will look at the actions of the Israeli military in light of international law.
More than 2,200 Gazans were killed during the fighting, approximately half of them civilians, according to a United Nations report.
The UN says approximately 1,500 were civilians, and the rest were militants. Israel disputes this number, saying half of those killed were militants.
Sixty-seven Israeli soldiers and six civilians were also killed during the war.
Since the end of the conflict, militant groups have occasionally fired rockets from Gaza into Israel -- and Israel has responded with tank fire and air strikes -- but the border has seen its quietest period in years.
The report is a political boon to Lapid, and to Naftali Bennett, leader of the Jewish Home Party and the current Education Minister in Israel's coalition government. Both were members of the Security Cabinet during the war, but, at least according to the findings, were left out of the decision-making process.
Bennett is vying with Netanyahu for leadership of the country's right-wing voter base, while Lapid, who sits in opposition, sees himself as a future contender for prime minister. When reached by CNN, Bennett had no comment on the comptroller's report.
Netanyahu, who has long prided himself on being the best leader for Israel's security, has tried to downplay or even dismiss the findings of the report.
The same can be said for Ya'alon and Gantz. Ya'alon, who left Netanyahu's Likud party after a public dispute with Netanyahu over the Israeli military, has made overtones of a return to politics in the next elections, perhaps with his own party.
Gantz, who left the military shortly after the Gaza war, may also explore his options in politics after a mandatory cooling-off period following his military service.