Not inherently; not by definition.
More often, nowadays: "anti-Israel" serves as a handy fig rhetorical fig leaf -- a nudge-nudge, wink-wink code phrase recognized and understood from one user to the next, like (oh, say) "neocon," for instance.
Alouette is -- as usual -- spot-on in her analysis of the topic at hand.
There have always been plenty of anti-Zionist Jews. They basically hold that "Israel" exists wherever Jews meet, and that Jews should stop dwelling on the physical location in the Middle East.
I tend to agree with them on principle, but after 9/11 it's no longer relevant anyway. Now, as a result of the Arabs' sponsorship of global terrorism in lieu of diplomacy, they should be forced to accept the State of Israel for *eternity*, just as an object lesson, and regardless of any argument over the merits of Zionism one way or the other.