The New York Times revealed in 1997 that the late Israeli defense minister, Moshe Dayan, had admitted 21 years earlier that the Golan was seized from Syria because Israeli farmers wanted more land, not because Syria posed a threat as claimed by Israel.

Here is a partial quote from General Dayan's 1976 interview:

"After all, I know how at least 80 percent of the clashes there started. In my opinion, more than 80 percent, but let's talk about 80 percent. It went this way: We would send a tractor to plow some area where it wasn't possible to do anything, in the demilitarized area, and knew in advance that the Syrians would start to shoot. If they didn't shoot, we would tell the tractor to advance farther, until in the end the Syrians would get annoyed and shoot. And then we would use artillery and later the air force also, and that's how it was"

This clip from a PBS documentary titled "50 years war, Israel and the Arabs" shows that it was in fact Syria that was feeling threatened by an Israeli invasion. The Soviets passed that information to the Syrians (and Egyptians) before Israel invaded its Arab neighbors in June 1967

At first, the war was really between Israel and the Egyptians. It was only later when Israel defeated the Egyptian army with ease, that it decided to take the Golan Heights as well, simply because Israel realized it was doable.

General Ezer Weizman, Israeli head of Operations, admitted in this segment of a PBS documentary titled "50 years war, Israel and the Arabs" that when Israel started the war, it was between Israel and the Egyptians, ...  "we did not plan to take the Golan"