Israel’s Prime Minister Benjamin Netanyahu on Sunday launched a blistering assault on Allied policy during World War II, saying world powers’ failure to bomb the Nazi concentration camps from 1942 cost the lives of four million Jews and millions of others.

Citing recently released UN documents that show the Allies were aware of the scale of the Holocaust in 1942, some two years earlier than previously assumed, Netanyahu said in a speech marking Holocaust Remembrance Day that this new research assumed “a terrible significance.”

“If the powers in 1942 had acted against the death camps — and all that was needed was repeated bombing of the camps — had they acted then, they could have saved 4 million Jews and millions of other people,” he said at the official state ceremony marking the start of the memorial day.

“The powers knew, and they did not act,” he told the audience at the Yad Vashem Holocaust memorial in Jerusalem.

“When terrible crimes were being committed against the Jews, when our brothers and sisters were being sent to the furnaces,” he went on, “the powers knew and did not act.”

Prime Minister Benjamin Netanyahu speaks at Holocaust Remembrance Day ceremony, April 23, 2017 (Yad Vashem screenshot)

Prime Minister Benjamin Netanyahu speaks at Holocaust Remembrance Day ceremony, April 23, 2017 (Yad Vashem screenshot)

In a bleak and bitter address, the Israeli prime minister said that the Holocaust was enabled by three factors: the vast hatred of the Jews, global indifference to the horrors, and “the terrible weakness of our people in the Diaspora.”

Anti-Semitism had not disappeared, and “it would be naive to think” that it would do so in the foreseeable future, he said. It was being exacerbated by “hatred from the East,” led by Iran and the Islamic State, he added.

The speech marked a sharp contrast from that of President Reuven Rivlin, who spoke just before Netanyahu, and cautioned against seeing anti-Semitism where it does not exist.

President Reuven Rivlin delivers a speech during a ceremony marking the Holocaust Remembrance Day on April 23, 2017 at the Yad Vashem Holocaust Memorial Museum in Jerusalem. (AFP/GALI TIBBON)

President Reuven Rivlin delivers a speech during a ceremony marking the Holocaust Remembrance Day on April 23, 2017 at the Yad Vashem Holocaust Memorial Museum in Jerusalem. (AFP/GALI TIBBON)

Global indifference persisted, too, Netanyahu said, as evidenced by the horrors in Biafra, Cambodia, Rwanda, Sudan and Syria. One “ray of light,” he noted, was US President Donald Trump’s determined response to Syrian President Bashar Assad’s gassing of his own people.

Chen and her 85-year-old grandfather Avraham, who is a Holocaust survivor, light candles next to a train wagon used in Nazi Germany to transport Jews to concentration camps, on April 23, 2017, in Netanya. (AFP/ JACK GUEZ)

Chen and her 85-year-old grandfather Avraham, who is a Holocaust survivor, light candles next to a train wagon used in Nazi Germany to transport Jews to concentration camps, on April 23, 2017, in Netanya. (AFP/ JACK GUEZ)

What had changed, though, was that the Jewish nation now has a strong Israel to protect it. “The weak do not have much chance of survival,” he said. “The strong survive; the weak are wiped out…our people learned this in the Holocaust.”

The lesson for Israel, he said, “is that we have to be able to defend ourselves, by ourselves, against any threat, against any enemy.”

He warned that “those who seek to kill us put themselves in the line of fire.”

That stance, he said, was “not a provocation or an exaggeration; it’s the only way to truly ensure our future.”

And that imperative, Netanyahu stressed, “is the prime obligation… of all Israeli prime ministers.”