‘ “And I will lay my vengeance on Edom by the hand of my people Israel, and they will do in Edom according to my anger and according to my fury, and they will know my vengeance”, says the Lord Yahweh.'
Here was a message of hope for Israel. For God's just judgment on Edom would come through the hand of Israel herself, and if that were to be so she had to be restored to the land. There are two kinds of revenge. One is thoughtless and indiscriminate going beyond what is justified. God would have no part in that. The other is measured and deserved, a measured response to a genuine offence given in accordance with the deserts of those on whom the vengeance is requited. That was what was intended here.
What we do know is that later Edom and its survivors were subdued by Judas Maccabaeus, and then by John Hyrcanus (later Jewish leaders), who incorporated them into the Jewish race by compulsory circumcision. Again they lost their nationhood. And all this would take place because of God's antipathy against their gross sin.