Albert Barnes Commentary Isaiah 14:26

"This is the purpose that is purposed upon the whole earth; and this is the hand that is stretched out upon all the nations." — Isaiah 14:26 (ASV)

This is the purpose—this is the sum of the whole design—a design that embraces the destruction of both the king of Assyria and Babylon.

Upon the whole earth—the successive kingdoms of Assyria and Babylonia embraced the whole earth, and to destroy them would in fact affect all the nations.