Did “many nations” attack Tyre, or just Nebuchadnezzar and Alexander?

“Yes, after all…
  • Alexanders forces were volunteers

    In addition to Alexander's Macedonians, forces were volunteered from multiple various nations in the siege of Tyre.

    Arrian of Nicomedia (ancient historian): “[Support came from] Aradus… Byblus… Rhodes… Sidonian triremes [from Sidon],… From Soli and Mallus… from Lycia… Not long after, too, the kings of Cyprus put into Sidon with about one hundred and twenty ships, since they had heard of the defeat of Darius at Issus, and were terrified.[The Anabasis of Alexander 19 (trans. by Chinnock, 2010)]

    Insofar as the forces volunteered on their own, we can properly say they were acting as independent nations. The number of nations involved in Alexander's attack, therefore, is more than one. It was several.

  • Tyre saw them as separate nations

    Tyre naturally saw Lycia, Sidon, Cyprus, etc. as a multitude of nations, attacking her from different angles.

    • Ancient historians saw it this way. (For example: Arrian of Nicomedia (ancient historian): “The Cyprians also sailed into the other harbour looking towards Sidon, …and made a speedy capture of the city on that side.[The Anabasis of Alexander 18])
    • Alexander likely saw it this way, as did the nations themselves. Specifically, Alexander saw some of these submissive city-states as simply making a gesture to get on his good side. He knew each, given the opportunity, would turn on him just as quickly as they currently were turning on the Persian king before him. A nation's choosing to submit to the latest overlord's wishes need not involve their being subsumed into the overlord's nation (in this case, Macedon).

    So even if you or someone else thinks the forces involved in Alexander's attack were technically not independent, the prophecy was a communication to Tyre and Tyre would have very much understood itself as being attacked by several neighboring nations.