The Israeli settlement of Efrat in the West Bank in 2014. (Ahmad Gharabli/Agence France-Presse via Getty Images)

Uri Blau is an Israeli investigative journalist based in Washington. Reporting for this commentary was supported by a grant from the Pulitzer Center on Crisis Reporting.

An office chair is positioned on the top of Dagan Hill, on the outskirts of Efrat, a thriving West Bank settlement. Someone must like to sit here and take in the changing landscape. Once-bare mountains are losing their shape, carved up by new roads and villas for a growing population of Jewish settlers.

Nadia Matar, one pillar of this community, should be happy. Twenty years ago, as she struggled to make a life on this hill, the success of her mission seemed improbable, if not impossible. Now, from the top of the windy peak, the fruits of her victory are apparent. Yet Matar, founder and leader of the pro-settlement nonprofit Women in Green, doesn’t sound cheerful when I call to ask about the funding of her organization. “Choose which side are you on,” she tells me in Hebrew, “ours, or the enemies who try to destroy us.”

Many from Israel’s far right and the settlers’ community condemn the Obama administration as that “other” side. They should know better: While one American hand opposes development of settlements, the other keeps feeding it.

A few miles away from Efrat sits the pleasant campground of Oz Vegaon, a West Bank outpost built without the required land allocation and planning permits from the Israeli Civil Administration. Campers, tourists and right-wing groups gather here to enjoy the newly constructed facilities. Women in Green helped to build Oz Vegaon last year, naming it after three Jewish teens murdered by Palestinians not too far from there. Some of the money it used on the site traveled some 5,700 miles from the center of Manhattan. Matar’s group is one of many settler organizations fueled with tax-exempt American dollars, of which increasing amounts arrive each year.

This year I conducted a thorough investigation into the complex network of tax-exempt donations helping to finance West Bank settlements. The investigation, published this month in Haaretz, looked at almost 50 nonprofit organizations that raise money in the United States for the settlements.

The findings are striking: Within five years, from 2009 to 2013, more than $220 million was sent across the ocean and into schools, synagogues and playgrounds dotting the hills of Judea and Samaria. Millions of tax-subsidized dollars have gone to Jewish settlements in Hebron, helping to sustain a grim reality in the segregated part of the city, where Palestinian movement is sharply restricted and their economic life has been suffocated.

Donations from the United States also were used to support families of Jews convicted in ideologically motivated violence against Palestinians. The spouse of Ami Popper, convicted of murdering seven Palestinians in 1990, received financial help from Honenu, an Israeli nonprofit that drew 20 percent of its income last year from U.S. donations.

The American donors to these groups are entitled to tax breaks on the money they give, and so this flow of funds means U.S. taxpayers are indirectly supporting a policy of settlement expansion opposed by the current administration and every other administration — Democratic and Republican — since Richard Nixon. In 2013, the organizations raised $73 million and doled out $54 million in grants. Initial data from 2014 suggest totals even higher.

In his 2009 speech to the United Nations, President Obama stated a clear view on Israeli presence in the West Bank. “America does not accept the legitimacy of continued Israeli settlements,” he said.

When I recently asked a senior White House official about this apparent contradiction, he told me: “This administration never defended or supported any activity associated with the settlements. It doesn’t support or advance any activity that will legitimize them.”

Plaques honoring American donors on buildings or promenades they helped to erect in the settlements suggest otherwise. If Obama means it when he warns Israel about the consequences of its settlement policy, he should explain why his country keeps subsidizing it.