I understand that France was an early ally of Israel after its creation in 1948, but helping it with developing nuclear weapons seems awfully risky in retrospect, contra simply helping to build up Israel's conventional military.
I'm thinking of risks like nuclear proliferation, France's geopolitical goals not always being aligned with Israel's, etc. Did France envision a world where every country would eventually develop nuclear weapons anyway, and it was just doing Israel a favour by helping it get them early on?
Until Charles De Gaulle took power in 1958, France still saw itself as by and large as a colonial power: besides the obvious example of Algeria, keep in mind that France, along with the UK, tried to intervene in Egypt in 1956. It identified with Israel as a Western power, with the Holocaust as a backdrop, and it was no secret that the Israeli leadership (remember, this is the camp generation) saw nuclear weapons as absolutely necessary. The Israeli government was far more Ashkenazi dominated back then, and largely dominated by the Labour Party, so they felt far more "European" than they do now. Thus, there was a natural tendency in France to help them, and for Israel to accept that help. There was also a pragmatic incentive for cooperation: Israel and France were outsiders looking in on the nuclear race, whereas the UK could rely more on the USA.
De Gaulle ended the "special relationship" because he took a far more nuanced view of future French foreign policy-see Algeria-and knew that France needed better relations with the Arab World. But the Israelis by the 60s were quickly developing a new partnership with the United States. They were able to build the bomb very quickly, not least due to world-class technical know-how. Confidence in this is why they can accept nuclear ambiguity.
One interesting additional point was that the President who worked out the tacit nuclear ambiguity deal with Israel, Richard Nixon(who incidentally strongly admired De Gaulle and in many ways had a similar political ideology), had that exact view of nuclear weapons in the developing world. Contrary to popular belief, Nixon didn't directly help the Israelis get nuclear weapons, given that was largely already a fait accompli by early 1969-hard to believe for Millennials, but back in those days the Democrats tended to be the knee-jerk pro-Israel party due to the presence of American Jews in the New Deal coalition and a far stronger focus on Jewish identity, especially after the Six-Day War-but he was willing to hammer out that deal, which more or less became an open secret in the world.