From the CIA’s journal “Studies in Intelligence” – Volume 49, Number 1, 2005 – comes an article by Dr. David S. Robarge who serves on the CIA History Staff. The article is entitled “CIA Analysis of the 1967 Arab-Israeli War
In the article Dr. Robarge debunks two central myths of the 6-day war: That Israel was in mortal danger, and that Israel acted purely in self-defense. He reports that The Mossad unsuccessfully tried to convince the CIA that it was outgunned and in danger of losing, and needed US support. The Mossad claim directly contradicted the CIA’s own intelligence analysis.

“Tel Aviv muddled this clear intelligence picture by submitting to Washington a Mossad estimate that claimed the Israeli military was badly outgunned by a Soviet-backed Arab war machine. The Israelis may have been trying to exploit the special relationship they had with James Angleton, chief of CIA counterintelligence. For years, Angleton had run the Israeli account out of his Counterintelligence Staff, without involving the Directorate of Plans’s Near East Division. That unusual arrangement may have given Tel Aviv a sense that Washington accorded its analyses such special import that US leaders would listen to its judgments on Arab-Israeli issues over those of their own intelligence services.”

However the CIA did not believe Israel was truly threatened by Egypt and Syria (referred to as UAR).

“The evidence was on the CIA’s side. Israel could not prove its case that the Arab armies would trounce it.”
[…]
“Informed by these assessments, President Johnson declined to airlift special military supplies to Israel or even to publicly support it. He later recalled bluntly telling Israeli Foreign Minister Abba Eban, “All of our intelligence people are unanimous that if the UAR attacks, you will whip hell out of them.”

I believe it’s a fascinating article, and I look forward to hearing your thoughts on it.