The left-wing philanthropist Alex Soros on Monday boosted a social media post from Max Blumenthal, a prominent anti-Israel conspiracy theorist who has spread misinformation questioning Hamas’ atrocities on Oct. 7, 2023, while promoting sympathetic coverage of Iran and Russia as well as the toppled Assad regime in Syria, among other authoritarian countries.

While the content of Blumenthal’s X post was relatively benign, citing a Washington Post report on concerns over American military casualties in the ongoing Iran war, Soros’ decision to elevate a known conspiracy theorist raises questions about the media sources he consumes, as he now leads a multi-billion-dollar grantmaking network that has funded a range of groups and causes shaping views on the Middle East.

Soros, one of the progressive movement’s most influential donors, has been outspoken against President Donald Trump’s unilateral decision to attack Iran in a joint operation with Israel, praising Spain for refusing to allow the U.S. to use bases on its soil and reprimanding other European countries for not doing the same. 

“Why aren’t more Europeans standing up to an illegal war! Same with Canada! They make nice speeches at conferences, but do little,” Soros wrote on X on Monday, saying Spain is “becoming the leader of the free world.”

The Open Society Foundations, which Soros, 40, inherited in 2023 from his father, the billionaire philanthropist George Soros, recently contributed $250,000 to establish a Middle East desk at Drop Site News, a media outlet that frequently publishes hostile coverage of Israel and credulous interviews with Hamas leaders. Drop Site has also amplified Blumenthal’s commentary.

Blumenthal, for his part, has spread false claims about the Hamas attacks — denying widespread evidence of sexual violence and suggesting Israel killed most of the victims during the massacre. He has pushed propaganda denying Syrian war crimes and China’s genocide of its Uyghur population. He regularly promotes pro-Kremlin talking points and appears on Russian television. A top editor for The Grayzone, his website, has received payments from Iranian media, according to The Washington Post.

After this story was published, a spokesperson for the Open Society Foundations told Jewish Insider that Soros had been unaware of Blumenthal’s background when he shared the post and was trying to highlight the Post’s reporting. He has since deleted the message from his X profile and shared a separate link to the same article.

A fact sheet posted to the Open Society website explicitly states the network does “not support Hamas,” saying “false accusations that are being repeated in some media circles in the United States” are “untrue.”

In January 2024, Soros, who is Jewish, wrote in an essay on his efforts to counter antisemitism that Open Society “has supported a diverse group of partners” with “different views on Israel and Palestine and what the peaceful resolution of the historic conflict might look like.”

“Their common bond: their belief that antisemitism — and also the disingenuous weaponization of the term to silence debate — presents a grave threat to democracy,” he added.

In addition to J Street, the progressive Israel advocacy group that is among the network’s top Middle East-related recipients, Open Society has given to organizations that have backed the Boycott, Divestment and Sanctions movement, according to NGO Monitor. 

More recently, Soros has voiced support for New York City Mayor Zohran Mamdani, a vocal critic of Israel who has long endorsed BDS campaigns.

Blumenthal, meanwhile, has also previously aimed his conspiratorial eye at Soros himself, claiming in a social media post shortly after the 2024 presidential election that the philanthropist “might have been an X factor in Trump’s victory.”

Story updated on March 4 at 9:55 a.m.