Vanished cities abound in Iraq —Babylon, Nineveh and Ur just for starters — so much that archaeologists joked that the only advice needed to uncover history is "just dig."

War and international sanctions closed these locations off to the world and to scholars. The ruins of ancient Mesopotamia, in modern-day Iraq, have mostly seen visits from looters for the last two decades.

But that may be changing. A U.S. archaeology team that was one of the first to visit Iraq in more than two decades, has just returned from a dig there. They are now among a growing list of other archaeologists returning to the war-ravaged nations.

"There is so much gloom and doom in news from Iraq, this is a really hopeful moment," says archaeologist Elizabeth Stone of Stony Brook (N.Y) University. "Iraq, Mesopotamia, is so rich in archaeological sites. It was wonderful to be back."...