What specific warnings did Israeli intelligence provide to the US before 9/11?

1. What the public record says about foreign warnings before 9/11

Several foreign governments and intelligence services warned U.S. authorities in 2001 that al‑Qaida was planning an attack on American soil, with varying degrees of specificity; scholarly summaries and compilations note alerts from France, Germany, the UK, Jordan, Egypt, Russia and Israel among others ^[1]. Those sources frame the Israel warnings as part of a broader mosaic of international intelligence indicating an elevated al‑Qaida threat rather than as an isolated, uniquely prescient tip ^[1].

2. The reported Mossad “list” and the timing of the alert

Contemporaneous reporting and later summaries reported that, in August 2001, the Mossad provided the CIA with a list—often cited as 19 names—of suspected terrorists believed to be residing in the United States and potentially planning an imminent operation; media accounts and later retrospectives attribute this transfer to Israeli intelligence but do not publish the original Mossad cable or CIA handling memos in full ^{[1] [2]}. The public descriptions indicate the warning focused on suspected individuals and a general assessment of an imminent al‑Qaida threat, not on operational details such as planned targets, dates, or the method of hijacked airliners ^{[1] [2]}.

3. Conspiracy allegations, the “art students” story, and official findings

A range of conspiracy narratives emerged after 9/11 claiming that Israeli agents or communities had precise foreknowledge—claims including that Jewish workers were warned to skip work at the World Trade Center and that an “Israeli spy ring” monitored U.S. targets—yet investigations and reputable watchdogs note these claims derive from dubious sources and have been debunked or unsubstantiated in official probes ^{[3] [4]}. The FBI ultimately treated several high‑profile arrests and investigations involving Israelis as foreign counterintelligence matters and concluded in specific cases that detained Israelis had no foreknowledge of the attacks, undermining broad claims of Israeli advanced warning ^[4].

4. Why the warnings that did exist were not translated into prevention

Analyses of the pre‑9/11 intelligence environment emphasize that even concrete‑sounding foreign warnings often lacked the tactical specificity required to disrupt an operation: warnings described an intent by al‑Qaida to strike inside the U.S. or listed suspicious persons, but did not identify the unique modus operandi—suicide hijackings using scheduled commercial flights—or provide a timeline that would permit focused interdiction ^{[1] [2]}. Contemporary critics and later commissions also pointed to structural problems within U.S. agencies—information silos and analytic failures—that limited the ability to fuse foreign tips into preventive action, a theme echoed across reporting about multiple pre‑attack warnings ^{[1] [2]}.

5. What remains unclear and where reporting is limited

Publicly available sources summarize Israeli warnings but do not make declassified original cables, full lists, or internal U.S. handling records widely available in the open reporting assembled here, so precise language, analytic caveats appended by recipients, and the full chain of dissemination inside U.S. agencies remain opaque in these sources ^{[1] [2]}. Because the provided sources do not include complete primary documents, it is not possible, on the basis of this reporting alone, to reconstruct the exact wording of Mossad’s communications, how U.S. analysts annotated or downgraded them, or whether additional, classified Israeli tips existed that have not been publicly released ^{[1] [2]}.