France had been a key weapons supplier to Israel during the 1950's and the first half of the 1960's. French fighter jets made up the backbone of Israel’s airforce on the eve of the Six Day War. Hoping to maintain its overseas empire in the face of mounting insurgencies, France had perceived common interests with Israel in confronting Arab nationalist fervor sweeping much of the Middle East and, in particular, its prized colony, Algeria.
Nevertheless, by 1967 positive relations between Israel and France had cooled. Charles de Gaulle's election in 1958 to the Presidency of France had begun a gradual shift in policy, a mending of relations with the Arabs and a move away from Israel. De Gaulle had judged that continued French rule in Algeria was untenable and he believed alignment with the Arabs would help France to re-assert itself as a global power, independent from either the American or Soviet camp.
Author David Pryce-Jones described the change this way:
Above all, de Gaulle aspired to great-power status for France, and toward that end he sought to maneuver between the United States and the Soviet Union, playing them off against each other and eventually removing France from NATO. The hope was that this brand of militant neutrality would muster the whole third world behind him. Pineau, the former foreign minister, spoke for many in noting that de Gaulle felt "a mortal hatred" for the British and the U.S. Increasingly resentful of the latter's projection of power in the Middle East, de Gaulle suspended aid to Israel's nuclear plant; played cat-and-mouse games over sales of arms and aircraft to Israel; and, after signing a peace treaty with Algeria, issued instructions to his new ambassador in Cairo to adopt "a more liberal attitude toward Nasser." When Abba Eban, the Israeli foreign minister, expressed anxiety in early 1966 over Israel's relationship with France, an irritated Couve de Murville replied that "General de Gaulle doesn't have to be patting you ceaselessly on the shoulder to reassure you."
...During the run-up to the [Six-Day War], France embargoed the delivery of offensive weapons to the Middle East, a move affecting only Israel. In a meeting with Abba Eban, de Gaulle warned Israel not to fire the first shot. ("They didn't listen to me!," he was to exclaim in anger and hurt pride a few days later.) He also told British Prime Minister Harold Wilson that the West would thank him one day for remaining "the only Western power to have any influence with the Arab governments."
After the war, Roger Seydoux, now France's permanent representative at the United Nations, lost no time declaring that Israel's reunification of Jerusalem was "inopportune and not founded in law." Israeli assurances of free access to the holy places "touched on questions of sovereignty to which we cannot remain indifferent." That November, de Gaulle ranted in public that the Jews were "an elite people, self-assured and domineering," and possessed of "a burning ambition for conquest." In the ensuing scandal, de Gaulle pretended that his abusive generalizations had been intended as compliments. (Commentary, May 2005)
De Gaulle's comments at the November 22, 1967 press conference are undeniably striking in their invoking of anti-Jewish tropes. (The original event can be viewed here.)
In addition to the embargo on Israeli weapons purchases imposed in 1967, France also refused to deliver 50 aircraft already paid for in full. Nor would France turn over a small fleet of torpedo boats bought by Israel. However, through a daring caper, the Israelis managed to spirit away the boats from under the noses of French authorities. The French embargo marked the end of close military relations between Israel and France and the beginning of a strong relationship between Israel and the U.S.
General References
Time Magazine, "DeGaulle's decision to impound Mirage Jets purchased by Israel," July 18, 1969