He was suddenly dispatched across the Pacific, without notice, to take over the American and allied military forces that had been battered and driven into a sometimes panicky retreat before the North Korean and Chinese armies.
It looked like an impending defeat with major international repercussions. But Ridgway somehow navigated through the military complications on the battlefield and the political complications at home, all at the same time, and saved the day.
A similar situation faced Gen. David Petraeus, who was appointed to lead a troop "surge" in Iraq, where things had gotten so out of control that virtually no one believed he could succeed.
Moreover, even when he did succeed, most of the media refused to believe it - until the facts about declining fatalities and a rising Iraqi economy made his success impossible to continue denying.
It is worth noting that those who made all-out political attacks on Petraeus during the surge included senators who are now the president of the United States, the vice president, the secretary of state and former Secretary of State Hillary Clinton.
All this is covered in "The Savior Generals."
Perhaps the book's most dramatic example of a turnaround in a militarily dicey situation was that of Gen. William Tecumseh Sherman during the Civil War.
The war was going so badly that some considered it doubtful whether the Republicans would even nominate Abraham Lincoln for a second term, and it was more than doubtful whether he could win reelection.
It was only after Sherman's unconventional, daring - and successful - march through Georgia, splitting the South in half, that Lincoln was reelected. It surprised everyone, including Lincoln.
"The Savior Generals" covers not only military history but also the social and political history that provides the context in which military events took place.
It leaves us a lot to think about regarding the issues and predicaments of our own time.
Sowell is a senior fellow at the Hoover Institution at Stanford University in California. His website is www.tsowell.com.