A choreographed military exercise in the capital of the United Arab Emirates drew hundreds of cellphone-filming onlookers Thursday — but they weren't the only intended audience for the re-enactment of a hostage rescue.

The pinpoint parachute drop and fast-rope assault on a ship from a helicopter, all overseen by a buzzing drone, showed the technical prowess of the UAE's military at a time when Gulf Arab countries are increasingly skeptical of Iran.

While hosting some 5,000 American troops, the UAE seeks to send a message to Iran that it remains capable of defending itself and launching assaults with its forces. That comes as Iran conducts military drills of its own and questions remain what approach U.S. President Donald Trump will take with the Islamic Republic.

The Emirati forces are now battle-hardened from the Saudi-led war in Yemen and the experience gained while serving in the U.S.-led coalition in Afghanistan.

Thursday's maneuvers, called Union Fortress, took place along Abu Dhabi's seaside corniche.

It featured fighter jets, helicopters and a mock seaborne hostage rescue performed by Emirati troops.

Last month, the UAE performed a staged assault as part of a biennial arms' fair called the International Defense Exhibition and Conference, known by the acronym IDEX. However, such maneuvers before the public are rare in the United Arab Emirates.

It offered no back story for the assault on the ship, other than a narrator describing a hostage-taking on board. Then came the theatrical gunfire on the shore, strafing runs by helicopters and armored carriers racing troops past onlookers for a raid.

An announcer offered poetry during some of the assault, while children wearing military uniforms played in the sand amid the explosions. ABC NEWS