This is a soul-searching moment for the Jewish left. Actually, for many Jewish liberals, navigating the gloomy politics of the Middle East is like walking with two left feet.

I would know. For six years I was the literary editor of Tikkun magazine, a leading voice for progressive Jewish politics that never avoided subjecting Israel to moral scrutiny. I also teach human rights at a Jesuit university, imparting the lessons of reciprocal grievances and the moral
necessity to regard all people with dignity and mutual respect. And I am deeply sensitive to Palestinian pain, and mortified when innocent civilians are used as human shields and then cynically martyred as casualties of war.

Yet, since 9/11 and the second intifada, where suicide bombings and beheadings have become the calling cards of Arab diplomacy, and with Hamas and Hezbollah emerging as elected entities that, paradoxically, reject the first principles of liberal democracy, I feel a great deal of moral anguish. Perhaps I have been naïve all along.

And I am not alone. Many Jews are in my position — the children and grandchildren of labor leaders, socialists, pacifists, humanitarians, antiwar protestors — instinctively leaning left, rejecting war, unwilling to demonize, and insisting that violence only breeds more violence. Most of all we share the profound belief that killing, humiliation and the infliction of unnecessary pain are not Jewish attributes.

However, the world as we know it today — post-Holocaust,post-9/11, post-sanity — is not

cooperating. Given the realities of the new Middle East, perhaps it is time for a reality check. For this reason, many Jewish liberals are surrendering to the mindset that there are no solutions other than to allow Israel to defend itself — with whatever means necessary. Unfortunately, the inevitability of Israel coincides with the inevitability of anti-Semitism.

This is what more politically conservative Jews and hardcore
Zionists maintained from the outset. And it was this
nightmare that the Jewish left always refused to imagine. So
we lay awake at night, afraid to sleep. Surely the Arabs
were tired, too. Surely they would want to improve their
societies and educate their children rather than strap bombs
on to them.

If the Palestinians didn’t want that for themselves, if
building a nation was not their priority, then peace in
exchange for territories was nothing but a pipe dream. It
was all wish-fulfillment, morally and practically necessary,
yet ultimately motivated by a weary Israeli society — the
harsh reality of Arab animus, the spiritual toll that the
occupation had taken on a Jewish state battered by negative
world opinion.

Despite the deep cynicism, however, Israel knew that it must
try. It would have to set aside nearly 60 years of hard-won
experience, starting from the very first days of its
independence, and believe that the Arab world had softened,
would become more welcoming neighbors, and would stop
chanting: “Not in our backyard — the Middle East is for
Arabs only.”

It is true that Israel has entered into peace agreements
with Egypt and Jordan that have brought some measure of
historic stability to the region. But with Israel having
withdrawn from Lebanon and Gaza, and with Israeli public
opinion virtually united in favor of near-total withdrawal
from the West Bank, why are rockets being launched at Israel
now, why are their soldiers being kidnapped if the
aspirations of the Palestinian people, and the intentions of
Hamas and Hezbollah, stand for something other than the
total destruction of Israel? And if Palestinians and the
Lebanese are electing terrorists and giving them the
portfolio of statesmen, then what message is being sent to
moderate voices, what incentives are there to negotiate, and
how can any of this sobering news be recast in a more
favorable light?

The Jewish left is now in shambles. Peace Now advocates have
lost their momentum, and, in some sense, their moral
clarity. Opinion polls in Israel are showing near unanimous
support for stronger incursions into Lebanon. And until
kidnapped soldiers are returned and acts of terror
curtailed, any further conversations about the future of the
West Bank have been set aside.

Not unlike the deep divisions between the values of red- and
blue-state America, world Jewry is being forced to
reconsider all of its underlying assumptions about peace in
the Middle East. The recent disastrous events in Lebanon and
Gaza have inadvertently created a newly united Jewish
consciousness — bringing right and left together into one
deeply cynical red state.

Mr. Rosenbaum, a novelist and professor at Fordham Law
School, is author, most recently, of “The Myth of Moral
Justice” (HarperCollins, 2004).