God has a future destiny for Israel.
Jesus spoke the words in Luke 21:20-24 some where around 30 A.D. In 70 A.D. the Romans invaded and destroyed Jerusalem.
From then on several Gentile rulers have controlled Jerusalem and was "trampled by Gentiles."
In 1918, a British General from the League of Nations controlled it.
In 1948, Israel was reformed as a nation, but it didn't include control of Jerusalem.
During the Six Day War, in 1967, Israel recaptured Jerusalem for the first time since 70 A.D.
The Area around the Temple Mount is still controlled by Muslins.