The former definition is being openly stated by the Israeli president, prime minister, and senior government officials as explicit justification for years of illegal settlements and apartheid.

The latter definition is a purely speculative excuse from Euro-American liberals that ignores that Palestinian Jews existed before Zionism in order to pretend that Jews can’t exist as part of a multiethnic society.

It's often used as newspeak. Just like in 1984, complex and often nuanced issues are reduced to simple words, soundbites or phrases which limit critical thinking and the ability to articulate more abstract or balanced opinions.

As you say, you're then forced to make a choice, because the whole thing's framed as a false dilemna.

Because the whole debate's so emotional and angry, any room for nuance is often dead on arrival, and gets buried in the cacaphony of the loudest and often most stupid voices.