Jerusalem was doomed:
Ezekiel 5:12 A third of your people will die in the city from disease and famine. A third of them will be slaughtered by the enemy outside the city walls. And I will scatter a third to the winds, chasing them with my sword.
But what was there for God to save?
The people were no longer worshipping God. Their wealth had been made into idols:
Ezekiel 7:20They were proud of their beautiful jewelry and used it to make detestable idols and vile images. Therefore, I will make all their wealth disgusting to them.
They also sinned against each other:
Ezekiel 7:23Prepare chains for my people,
for the land is bloodied by terrible crimes.
Jerusalem is filled with violence.
Israel had abandoned any pretence of obeying God and His commandments. It meant that when the enemy came against Israel, as always happens when a military expansionist state like Assyria or Babylon sees land and wealth and wants it, God would have nothing worth defending.