Blessed are the Peacemakers

At the time when Jesus preached the Sermon on the Mount to his disciples, Judea had been fully under the control of the Romans for almost 100 years.  That is from now back to 1920.  Before that, except for a short but tumultuous period of self-rule, from the time of the exile, they were ruled by the Babylonians, then the Persians, then the Greeks, and now the Romans.  All Israel was looking for the Messiah to come, to conquer the foreign rulers, and set up the kingdom of God as a material kingdom on earth.  An independent Judean state under self-rule.  That is what they were looking for and they wanted it badly.