Mt. Olivet Discourse: The Great Tribulation

Jesus, in warning about the coming desolation of Jerusalem and the Temple, speaks of a great tribulation. Is this period still in the future? Or, as the text indicates, is the Great Tribulation a period of time already passed, the time when the Jews were surrounded by the Romans in AD 70, and the city and temple destroyed? Jesus uses language from the Old Testament here, to demonstrate the utter catastrophe that would soon come upon Israel.