The US army base in the UAE was emptied before the war on Iran because the UAE refused to support in any way, shape or form any aggression towards their neighbour. Also, the heavy defenses they had was removed and taken to Israel in expectation of a counter attack back after Israel and America attack Iran. Iran attacked and flattened empty US army bases in the UAE, and then started attacking oil fields, airports, seaports, hotels and civilian structures in the UAE.
The UAE has an excellent defense system and is receiving 60% of the attacks of the missiles and drones from Iran, while Iran is sending 15% of the attacks to Israel. The Emirates has been defending itself and not attacking Iran despite proving that its land, sea and air is not used to attack but Iran persists and continues to attack its peaceful neighbor.