Rebecca West (1892–1983) and Dorothy Thompson (1893–1961), both world-class journalists, were “new women” who sought not only to match the exploits of their male contemporaries, but to become, in the current argot, “brands.”

West turned her coverage of the Nuremberg trials into a profound inquiry into the nature of international justice, exposing the problematic and yet justifiable process of judging war criminals. The Allies, too, were guilty of atrocities, West pointed out—even as she provided the rationale for their sitting in judgment against their Nazi enemies. Her reports on the postwar treason trials put her on the cover of Time, adorned in a helmet-like hat that emphasized her militant pursuit of international events that she alone seemed able to absorb into her capacious and extraordinarily articulate sensibility.

Thompson, who befriended West in Germany as the Nazis were coming to power, quickly perceived Hitler’s monstrous ambitions. She also saw that his vague, shallow, and malign politics would bring the world to grief. In a column for the New York American in the early 1930s, West told her readers to buy Thompson’s prescient book I Saw Hitler! (1932). Thompson, the subject of a Time cover story in 1939, was hailed as one of the most influential woman in America, second only to Eleanor Roosevelt.

Of course, other women journalists before and after West and Thompson have had remarkable careers, but none of them can quite match the fame and influence that Thompson enjoyed in the late 1930s and West experienced a decade later. Beginning in 1936, Thompson’s “On the Record” column in the New York Herald Tribune provided readers, three times a week, with an outspoken point of view on world events. Although Thompson was, as Susan Hertog rightly notes, classically liberal in her concern for minority rights and constitutional government, these attitudes did not prevent Thompson from becoming one of the New Deal’s most outspoken critics. She distrusted Roosevelt’s new programs and believed that his plan to pack the Supreme Court with justices sympathetic to his policies was not simply an overreach but an indication of a man who would run roughshod over the Constitution. Even so, when it came to deciding between Wendell Willkie and Roosevelt at a time when the latter was severely criticized for seeking a third term, Thompson broke ranks with her conservative Republican supporters and endorsed the President, arguing that Willkie was just not up to the job.

As Hertog shows so well, Thompson remained her own woman—as did West, who stood up to the liberal orthodoxy of her day by, for example, telling off Arthur Schlesinger, Jr. when he tried to lecture her on anti-Communism and on her supposedly pro-Joseph McCarthy attitudes. West may have begun her career as a socialist and a feminist and would remain, in certain respects, on the left, but she never hesitated to break with the so-called progressive movements—perhaps most notably when she perceived early on that Henry Wallace, the Progressive Party candidate for president in 1948, had become a tool of the Communist Party.

But in what sense was the ambition of these two women “dangerous”? And why write a book about both of them, since Thompson and West have already been, as Hertog acknowledges, subjects of excellent biographies? Thompson was thrown out of Germany because she would not shut up—not even after she was warned about her behavior by the Gestapo and given twenty-four hours to leave the country. West was nearly as intrepid, navigating London streets where she heard herself denounced by Oswald Mosley’s fascist mobs. In Greenville, North Carolina, when a local advised her that covering a lynching trial was not the safest form of journalism, West responded by buying him a box of candy—her way of saying she was there to stay and had not come to the South with the usual kinds of prejudices Southerners had come to expect.

But Hertog has in mind another kind of danger. West and Thompson sacrificed personal happiness, even as they won the admiration of the world. Both of these astute women made terrible choices when picking lovers, settling on men who valued their genius and yet also sought to demean it. This attitude is especially clear when it comes to H. G. Wells, who really would have preferred that his Rebecca write whimsical, fantasy novels like Harriet Hume (1928) than engage in political analysis.

Thompson, for her part, made the mistake of marrying the alcoholic Sinclair Lewis, who professed great admiration for Thompson’s work and yet really wanted her to stay home and support his genius. Later, Thompson was happily married to the artist Maxim Kopf, a man who revered her genius. West’s marriage to the banker Henry Andrews began well, although their partnership attenuated as he became infatuated with young women, especially dancers.

Lovers aside, these women’s lives ended unhappily because of their fraught relationships with their sons. In writing about Thompson’s son, Michael, and of West’s son, Anthony, Hertog provides the best account I have yet read of what it meant to these women to pursue their ambitions, even as they insisted they could also be good mothers. They could not. Hertog neither blames nor exonerates Thompson and West. Instead, she provides meticulous, compassionate, but also critical portraits of self-deception, of women eager to fly off to cover the latest controversies—all the while supposing they could return home to children who would appreciate how much their mothers had done for them in terms of good homes, good schools, and abundant opportunity. When Thompson tried to show West why she might be offending Anthony, West took offense, and vice versa. Neither woman was able to engage in self-inspection. Indeed, they were used to projecting their anxieties onto the canvas of the world stage, using their troubled sensibilities to explain the world at large.

Above all, Susan Hertog shows how difficult it was even in the last century to be a high-functioning woman in the charged arena of national and international politics. This is where her dual approach marks an advance over previous biographies. It was not just West, not just Thompson, who ran into trouble: That trouble was built into the very world they reported and shaped.