Once again, what is the line that separates legitimate criticism of Israeli policies towards Palestinians and simple antisemitism?

Eve Garrard lines up her exhibits, on Normblog today:

What is really noticeable is the mismatch between what pro-boycotters, and the
Union itself, say about anti-Semitism and the proposed boycott, and what seems
to be actually going on among some of the boycott's supporters. Whether through
ignorance or malice, some of them are telling flagrant and disgusting lies about
Israel, lies which express some very familiar anti-Semitic tropes. But the
Union's view is that saying that Israel is the root of all evil just can't be
construed as anti-Semitic. And saying that Israel is the most inhuman country in
the Middle East, and that it's the cause of all the world's troubles, can't be
anti-Semitic either. Saying that Israel's supporters have bought America's
government can't be anti-Semitic. Saying that Israel is equivalent to the Nazis
can't be anti-Semitic. Saying that Israel is committing genocide can't be
anti-Semitic. Saying that Israel should be wiped off the world map can't be
anti-Semitic. Really, you begin to wonder what the Union would regard as
anti-Semitic.

Norm Geras takes up one point to expand upon:

Denying that the Jews were the victims of a genocide now has its counterpart in
the allegation that the Jewish state is perpetrator of a genocide against
another people. And this is not a case where the evidence is borderline. Just
like Hocaust-denial, genocide-assertion as applied to Israel vis-à-vis the
Palestinians bears no relation to any serious historical evidence about the long
conflict in the region. It is a blatant historical falsehood - the blood libel on
a spectacular scale. Genocide-assertion with reference to Israel should be seen
henceforth as the twin of Holocaust-denial: a not very covert form of
anti-Semitism that disgraces its proponents.

In 2004, the European Monitoring Centre on Racism and Xenophobia (EUMC) called attention to the lack of a common definition of anti-Semitism. Consequently, a working definition was written collaboratively by a small group of non-governmental organizations (NGOs):

Denying the Jewish people their right to self-determination, e.g., by
claiming that the existence of a State of Israel is a racist endeavor.

Applying double standards by requiring of it a behavior not expected or
demanded of any other democratic nation.

Using the symbols and images associated with classic antisemitism
(e.g., claims of Jews killing Jesus or blood libel) to characterize Israel or
Israelis.

Drawing comparisons of contemporary Israeli policy to that of the
Nazis.

Holding Jews collectively responsible for actions of the State of
Israel.

And further to Eve Garrard's and Norm Geras's points, here is Christopher Caldwell (Weekly Standard, June 5, 2002) on same:

“For anyone who inhabits Western culture, the Holocaust made that culture a much
more painful place to inhabit – and for any reasonably moral person, greatly
narrowed the range of acceptable political behaviour. To be human is to wish it
had never happened. (Those who deny that it did may be those can’t bear to admit
it happened,) but it did. If there is a will-to anti-Semitism – then the Arab
style Judeophobia, which is an anti-Semitism without the West’s complexes,
offers a real redemptive project to those Westerners who are willing to embrace.
It can liberate guilty, decadent Europeans from a horrible moral albatross. What
an anti-depressant! Saying there was no such thing as the gas chamber is, of
course, not respectable. But the same purpose can be served using what Leo
Strauss called the reductio ad Hitlerum to cast the Jews as having committed
crimes identical to the Nazis’. They must be identical, of course, so the work
of self-delusion can be accomplished. We did one, the Jews did one. Now we’re
even-steven”.

This is why one may find Israel being facilely and baselessly accused of "crimes against humanity", or Jews jeered at for being offended by the Islamic instruction to the believers that the Jews are “the enemies of Allah, descendants of apes and pigs.” It is because, as Nick Cohen explains in "What's Left,:

[b]eyond the release from the burden of the past, lay the relief of
letting out repressed emotion.... Once … a figure or group became
an approved object of hatred, pent-up feeling burst over it. "