Is Israel's neutrality in the Russia-Ukraine war immoral?

The 27-year war between Athens and Sparta was in its 15th year when the Athenians, out to cement their grip of the Aegean Sea, demanded that the island of Melos – about halfway between Athens and Crete – surrender to their rule. 

The Melians refused; not because they sided with one of the war’s sides, but because they sided with neither. “Neutral,” they said they are, and while that meant “being friends instead of enemies,” it also meant being “allies of neither side” (Thucydides, History of the Peloponnesian War, 5:94).

The Athenians rejected the idea, and while at it stated what still reads like imperialism’s motto: “The strong do what they can and the weak suffer what they must.”