And yet the enemy ranks are filled with women who are not just a ladies' auxiliary but, in some cases, the most dedicated warriors -- many of whom consider themselves feminists.

Women head nearly a third of the state chapters of the Children's Rights Council, which purposely avoids the "father's rights" label but is often tagged with it nonetheless -- with good reason. (The CRC's advocacy of shared parenting regardless of marital status clearly translates into support for an expanded role for noncustodial parents, usually men, and overlaps with the agenda of most fathers' groups.)

The executive director of the American Coalition for Fathers and Children, a national umbrella group, is Dianna Thompson, a political consultant in Orange County, Calif. (Full disclosure: I have an unpaid honorary post on the ACFC advisory board.) The ACFC says that women make up about half of its membership. There also is a recently founded group with the self-explanatory name Women for Fatherhood.

At the state level, the picture is much the same. Three of the four active chapters and two of the four currently forming chapters of the Coalition of Parent Support (COPS), a California advocacy group for noncustodial parents, are run by women; so are three of the 10 chapters of Fathers Are Parents Too in Georgia.

How do these women become fathers' rights advocates? Ironically, in many cases, their backgrounds fit the feminist model of activism and public advocacy rooted in personal experience -- in this instance, a close relationship with a man who they believe has been victimized by the divorce courts. No less ironically, some have been inspired by their personal experiences to take action that looks very much like the kind of empowerment feminists have preached: Many, for instance, go to law school.

Thompson was galvanized into activism in 1992 when, as a result of an overhaul of California's child support laws, her husband's support payments for two children from his first marriage were tripled. Thompson, a mother of five, says that as a result of the increase, her family was faced with losing their home.

"This is when I saw firsthand the system's lack of concern for children's best interests," says Thompson, who stresses that she never begrudged child support to her husband's children from his first marriage but considered the new amount to be outrageously excessive. "That is when I said to myself: This is wrong and I can't allow this to continue."

In 1993, she joined COPS, which successfully lobbied for a state law that would exempt the earnings of the noncustodial parent's current spouse from the amount used in calculating child support obligations. (Fathers' advocates point out that in most states, the income of the custodial parent's new spouse is not used in calculating the children's needs.)

The motives of the "second wives crusade" -- which happens to be the name of a Web site that Thompson has built -- are easy to impugn. It would be tempting to dismiss these women either as selfish and greedy (and too shortsighted to realize that someday they too may find themselves dumped and struggling to collect child support) or as vindictive toward their rivals. Some would insist that they are dupes of manipulative men who portray themselves as victims and their ex-wives as bitches from hell.

To many feminists, this is a classic example of the patriarchy's using women to do its dirty work and pitting them against one another. Susan Faludi has compared activist second wives to blacks who criticize affirmative action, implying that both are Uncle Toms ("So many women still depend on men for their financial and social sustenance, there will always be women who are willing to play that role"), while NOW executive vice president Kim Gandy has suggested that the men use their female supporters as a front, just as "a man charged with rape will hire a woman lawyer to represent him."

Yet, listening to the second wives and girlfriends, it is hard to defend that simplistic view. Some of them (Thompson, for one) are all too familiar with the other side of the divorce wars, having been single mothers raising children on their own. Some, such as COPS activist Robin Welch, have stood by husbands who fought to have their children from the first marriage live or at least spend more time with them -- something a wicked stepmother would hardly encourage. And it's hard not to be impressed with the desperate sincerity with which many of these women assert that their real concern is for children who, they say, are visibly suffering from the disruption of the father-child bond.

Order "Mothers Who Think: Tales of Real-Life Parenthood" from the editors of Mothers Who Think.