I could not find any such speech from Abba Eban, and it is possible that Massad is referring to this 1975 New York Times article that Eban wrote right before the infamous UN resolution equating Zionism with racism. Eban's words are not a "strategy" but a statement of fact.
Let me put it this way: the anti-Zionism-is-antisemitism formulation describes the Jewish identity of tens of thousands of Jews as illegitimate. My great-great grandfather was one. He was chief rabbi of Boston. He opposed Zionism until the day he died. He was even challenged to a duel by Chaim Weitzmann, whose friends apologized profusely. The only universe where all Jews are Zionists is where nationalists mute everyone with contrary opinions. Which is what Eban was trying to do here.
The people making this argument are being disingenuous.
Before 1948, there was a fierce debate in Jewish circles about whether a Jewish state was good for the Jews. Both religious and non-religious Jews weighed in. There were significant fears about whether such a state would increase antisemitism, whether Western nations would expel their Jews for the Jewish state (no one argued in those days that Jews were not a nation,) as well as religious objections to creating a Jewish political entity before the Messiah comes.
But all of that changed when Israel became a reality. Jewish anti-Zionism became a fringe movement immediately. Only antisemites argued that the existing Jewish state must be dismantled or destroyed.
This 1968 story from a biography of the anti-Zionist Satmar Rebbe illustrates how even the religious Jews who were against the idea of Israel understood that anti-Zionism that was not from a religious Jewish perspective was bigotry:
When Hubert Humphrey was running for president in 1968, he came to speak with the Rebbe. The Rebbe noticed the chassidim whispering to Humphrey, and after the meeting he asked them what they had been saying. They said that they had warned Humphrey prior to the meeting that the Rebbe strongly opposed the State of Israel, and therefore Humphrey should avoid that subject. Humphrey had then asked if he could at least tell the chassidim about his support for the state, and they had laughed. The Rebbe said, "Had he spoken to me in support of the state, it wouldn't have bothered me in the least. We Jews have a Torah which forbids us to have a state during exile, and therefore we cannot ask the Americans to support the state. But a non-Jew has no Torah, and by supporting the state he feels he is helping Jews. And on the contrary, if an American non-Jew is against the Zionist state, it shows he is an anti-Semite." (h/t @yesh222)Even the most prominent Jewish anti-Zionist understands that when non-Jews and non-religious Jews oppose Israel, they are simply antisemites.