During the earliest years, it was Czechoslovakia that was Israel's critical ally (the Czechs supplied all the first-line aircraft for the Israeli Air Force for example). They supplied military equipment to the fledgling country when nobody else would. Then it was the French through 1966 that was the primary arms supplier. de Gaulle pulled out of that arrangement when France left their remaining colonial possessions in N. Africa. It was at that point the US stepped in.
By 1975 Israel was well on their way to supplying most of their own military needs internally. They had, or were on the verge of, manufacturing a supersonic fighter aircraft, a first-line battle tank, APC's, small arms, artillery, and then onto PGM's of various sorts.