Though most are not as nightmarish, adoption complications are common. Some adoptive parents have even hired private investigators to try to verify the stories they were told about their kids.

When scandals emerge, governments lumber into action. But then the demand just shifts to another country, and the problems start all over again. In the early 1990s, Romania saw an adoption boom after shocking images of orphanages — housing young victims of Nicolae Ceausescu’s compulsory birth policies — became public. But over time, stories of other Romanian kids’ being coerced into adoption or bought from their families surfaced. Romania halted international adoptions in 2001.

Also in the 1990s, the number of adoptions from Vietnam soared, but the outrageous fees paid to child finders — sometimes more than $10,000 — caused the government in 2003 to press pause to reform the system. (But when the adoptions resumed in 2005, so did the problems.)

At the height of Guatemala’s adoption boom in the middle of the last decade, nearly 1 percent of babies were sent to the United States, before stories of child buying and even kidnapping prompted a shutdown in 2008. Then the boom shifted to Ethiopia and, now, Uganda and the Democratic Republic of Congo.

Of course, adoption problems aren’t limited to Christian agencies, and they don’t originate with them, but some movement insiders say that evangelicals — whether driven by zeal or naïveté — have had a disproportionate impact on the international adoption system. Groups like Unicef and Save the Children have made clear that millions of “orphans” are, in fact, not eligible for transnational adoption, but advocates often disregard these warnings as signs of ideological opposition to adoption — a charge Unicef has denied.

After some high-profile adoption horror stories, the number of transnational adoptions to the United States fell to fewer than 9,000 last year, from a high of nearly 23,000 in 2004. Last year, only China and Ethiopia sent more than 1,000 adoptees to America, and only South Korea and Russia topped 500. (Russia this year banned adoptions by American parents.)

This boom-and-bust, musical-chairs cycle does little to improve child-welfare systems in developing countries and has perpetuated a culture of aid-based orphanage construction — the reverse of the trend in wealthy countries, which have phased out institutions in favor of foster care.