Is the whole human race guilty of crucifying Jesus, not only the Jewish nation?
Yes. Scripture indicates the kings of the earth and the people consorted together, so the whole human race is guilty of crucifying the Messiah. Peter specifically charges the house of Israel on covenant ground because they should have known better, yet the broader guilt extends to all humanity.
Les teaches that Peter, in Acts 2:36, tells all the house of Israel to know assuredly that God made the same Jesus whom they crucified both Lord and Christ. Peter repeatedly lays the blame for the crucifixion on the Jewish nation, and they did precipitate it. But Les says never lose sight of Psalms chapter 2, verse 1, where the kings of the earth and the people consort together; therefore the whole human race is guilty of having crucified the Messiah. Peter is dealing with Israel on covenant ground, pointing out that they, who should have known better, rejected the one God sent to fulfill the Abrahamic covenant. When they heard this, the Spirit convicted them and they were pricked in their heart.
Why do the heathen rage, and the people imagine a vain thing?