When an individual Jew receives Christ, i.e., believes on the death, the burial and the resurrection (1 Corinthians 15:1-4), the cycle is broken. Those that reject Jesus Christ continue in the traditions that damn them in the first place. The Jews, as a nation, brought upon themselves a curse from God (lack of His blessings), but as individuals they have a choice to make.
He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him. (John 3:36)
Yet I was addressing the inference of the Jews, though not a nation, being punished with the holocaust as a result of "let His blood be on us, and on our children,” (Matthew 27:25) versus Deuteronomy 24:16; cf. 2Ki 14:5,6; 2Ch 25:4; Jer 31:29,30; Eze 18:20.
Although being subjected to punishment (the Muslims neighbors being one agent of that) and "as concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers’ sakes" (Romans 11:28) and thus God showed them grace by bringing then back into part of their land, and clearly aided them in defeating Muslim onslaughts and thereby preserving their nation. Despite their own sins, as with those of the West.