It is told that Elendil stood there watching for the coming of Gil-galad out of the West, in the days of the Last Alliance.
But Sauron of Mordor assailed them, and they made the Last Alliance of Elves and Men, and the hosts of Gil-galad and Elendil were mustered in Arnor.
Fruitless did I call the victory of the Last Alliance?
How I would drive the hosts of Mordor, and all men would flock to my banner!’ Boromir strode up and down, speaking ever more loudly: Almost he seemed to have forgotten Frodo, while his talk dwelt on walls and weapons, and the mustering of men; and he drew plans for great alliances and glorious victories to be; and he cast down Mordor, and became himself a mighty king, benevolent and wise.
There are no more uses of "alliance" in the book.
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The Islamic governments formed an alliance to defeat Israel.