A new report from Haaretz reveals that, from 2009-2013, US donors gave at least $220 million to Israeli settlements in the occupied West Bank, a scheme that is run through scores of US-based nonprofit groups who accept the donations as tax deductible.

The money was largely sent to settlements as grants, allowing them to spend money on whatever they want, be it construction or legal aid for convicted terrorists backed by the settler movement. This included Honenu, an Israeli settler group that supports the families of Israelis imprisoned for killing Palestinians, and also raised money for Yigal Amir, who assassinated former Israeli PM Yitzhak Rabin.

The tax deductible status of the settlement donations is raising some eyebrows, since the settlements themselves are illegal under international law, and not recognized as legitimate under US law either. Every administration since 1967, when the West Bank was occupied, has been at least nominally opposed to settlement expansion.

The money ultimately means that even as the White House insists they oppose the settlements, and are making it a matter of policy that those settlements imperil the peace process, the US is also ultimately behind a good chunk of the funding keeping the illegal endeavor going.

Awash in money from US donors, the settlements are politically powerful in Israel, backing far-right political parties who support seizing more territory from the Palestinians and expanding the settlements deeper into that territory. The tie between Israel’s far-right and the settlements has also made being pro-settlement a popular position in the Republican primary, with many hoping to get on the same gravy train of donors that the settlements are already on.