There is today a huge Jewish population in Palestine whose rights as human beings must be recognised, but why should anyone anywhere be compelled to recognise the "right to exist" of a particular state formation? What's being demanded here is ideological conformity: support for the right of the Jewish state to exist, in perpetuity, in Palestine, regardless of what that fact entails for others (or indeed for the welfare of Jews). For Palestinians, recognising Israel's right to exist -- as opposed to the fact of its existence -- is tantamount to an historical seal of approval on the Nakba. Those who refuse to certify as legitimate a national project built on dispossession and ethnic supremacy are condemned as "anti-Semites" or, if they are Jews, as "self-haters". The allegations rest on a false conflation of Israel and "the Jews", one propagated by Zionists, who use it to exempt the Jewish state from the requirements of international standards of human decency.
Israel is "Jewish" in a sense that no existing state is Christian, Muslim, Hindu or Buddhist. Though these religions are privileged in various states, none of those states claims to be the sole global representative of the faith; none grants citizenship to people solely because of their religion (without regard to place of birth or residence). Maintaining a Jewish state in Palestine means maintaining a sizeable Jewish majority population which enjoys privileged access to land, work and civic rights.
The founders of Israel were secularists; they saw Jewishness as a national rather than religious identity. Many were atheists and contemptuous of rabbinical culture. Like MA Jinnah, the secular Muslim founder of Pakistan, they would be shocked and dismayed if they could see the influence obscurantist religious sects now wield in the polities they established.
From the beginning, the notion that the State of Israel could be both "Jewish" and "democratic" was unsustainable, and was seen as such by significant numbers of diaspora Jews. Indeed, it's important to remember that anti-Zionism was a Jewish ideology long before it was anything else. But in the wake of the Holocaust, and with the evolution of big power politics in the Middle East, Zionism came to dominate the diaspora. And the truth of the Nakba was shrouded beneath the myth of Israel's "David versus Goliath" struggle for survival against irrationally hostile Arabs.
But what of the plight of the Jewish refugees in postwar Europe? Without Israel, what would have become of them? The answer is that they would have shared the same variety of fates as the general refugee population of Europe, of which they were part. The roots of that crisis lay in the refusal of the US, Britain and other countries to admit large numbers of displaced persons. It could not be resolved by allocating each group a "state of their own", inevitably at the expense of another people. The right of refuge is a universal right (and need) but instead of shouldering that collective responsibility, the Western powers, with the support of the Soviet Union, dumped it on Palestine, demanding that a people who bore no responsibility for the Holocaust make way for its victims.
Many Zionists who do acknowledge the Nakba characterise it as tragic but "irreversible". The Nakba was not, however, an isolated episode; it was a paroxysm in a process that continues to this day. The Jewish state remains incompatible with Palestinian rights and increasingly the very existence of Palestinians, as illustrated by the current siege of Gaza and the continuing assault on Palestinian society on the West Bank through the construction of the apartheid wall and the extension of Jewish settlements.
It has become ever more apparent that Zionism will not tolerate any meaningful form of Palestinian independence. The exigencies of maintaining a Jewish state will not allow it. Within Israel, expansionist claims -- in which the Jews are declared the rightful owners of the whole of the West Bank and even beyond -- are commonplace, as are calls for the permanent transfer of the remaining Palestinian population. Some respectable voices speak openly of the need to finish the work left undone in 1948 -- in order to ensure the survival of "the Jewish state".
As ever, much of this is cloaked in Biblical sources. The paradox of Zionism was always that it was a secular ideology whose foundation lay in a religious discourse. At its heart is an obscurantist claim to historic territory. There is indeed much in the Hebrew Bible that gives succour to the wilder Zionist ambitions. But there is also another strand, one that warns against the menace of marrying religion to the state. In particular the Prophet Amos, a champion of the universality of ethical standards, explicitly denies the exclusivism of the Zionist claim to Palestine:
To Me, O Israelites, you are Just like the Ethiopians -- declares the Lord. True I brought Israel up From the land of Egypt, But also the Philistines from Caphtor And the Arameans from Kir.