46 Children Were Taken From Ukraine. Many Are Up for Adoption in Russia.

“Navigator,” the man who had ordered the children removed from the church, visited the foster home repeatedly. He would later be identified as Igor Kastyukevich, a Russian member of Parliament from Mr. Putin’s political party, United Russia.

Anna Kuznetsova, a deputy chairwoman in the Russian Parliament and Ms. Lvova-Belova’s predecessor as children’s rights commissioner, traveled from Moscow to deliver baby products on behalf of the party. “#WeDon’tAbandonOurOwn,” she wrote on Telegram, using a pro-war hashtag to suggest that the children belonged to Russia.

In interviews with The Times, Russian officials echoed that view, saying that the children from Kherson were Russian.

In May, Mr. Putin fulfilled his promise to Ms. Lvova-Belova by issuing a presidential decree that eased citizenship requirements: In Kherson and other occupied regions, Ukrainian caregivers could now file for Russian citizenship on behalf of Ukrainian foster children and orphans.

The decree also expedited the process so that children could become Russian citizens in 90 days or less, instead of up to five years.

The next month, Ms. Korniyenko, the director of the foster home, was summoned to Kherson’s Ministry of Health, now run by the occupation authorities. A Russian-backed official asked her to remain the director, but under his supervision. She was even offered a Russian passport.

But Ms. Korniyenko refused. She’d had enough of the occupiers, who, she said, intimidated the staff by asking them about their political views in a test of their allegiance and carried guns while monitoring the children.

Dr. Lukina resigned, too. She cared deeply about the children, but she didn’t want to have any role in what Russian-backed officials might do to them.

“I didn’t want to take part in it,” she said. “And I was afraid that they would take me away as well.”

In search of a new director, the occupation authorities turned to Dr. Tetiana Zavalska, a pediatrician at the foster home who often worked night and weekend shifts. She was sympathetic to the new occupation administration and made clear her pro-Russian views.