I’ve been hunting around for the answer to this question a bit lately. Chomsky did an OK job, responsibly (and more-or-less accurately) warning against a potential death toll rising to the hundreds of thousands. But he seems to have been a bit squishy on the chemical and biological weapons issue, advancing a healthy but not especially focused skepticism about their existence. And I was unable to find predictions of sectarian strife leading to civil war.

Then I came across this excellent posting by Glenn Greenwald, who reminds us of Howard Dean’s prewar position:

when one reviews the pre-war arguments made by Howard
Dean as to why the war was ill-advised, it is glaringly self-evident
just how right he was — at a time when few others recognized it —
about virtually everything. Here are excerpts from a speech Dean gave
on February 17, 2003 — just over a month before we invaded — at Drake
University which reflects the prescient warnings he was making back
then:

[…]

The Administration has not
explained how a lasting peace, and lasting security, will be achieved
in Iraq once Saddam Hussein is toppled.

I, for one, am not ready to abandon the search for better answers.

[…]

We have been told over and over again what the risks will be if we do not go to war.

We have been told little about what the risks will be if we do go to war.

If we go to war, I certainly hope the
Administration’s assumptions are realized, and the conflict is swift,
successful and clean. I certainly hope our armed forces will be
welcomed like heroes and liberators in the streets of Baghdad.

I certainly hope Iraq emerges from the war stable, united and democratic.

I certainly hope terrorists around the world conclude it is a mistake to defy America and cease, thereafter, to be terrorists.

It is possible, however, that events could go differently, . . . .

Iraq
is a divided country, with Sunni, Shia and Kurdish factions that share
both bitter rivalries and access to large quantities of arms.

Anti-American
feelings will surely be inflamed among the misguided who choose to see
an assault on Iraq as an attack on Islam, or as a means of controlling
Iraqi oil.

And last week’s tape by Osama bin Laden
tells us that our enemies will seek relentlessly to transform a war
into a tool for inspiring and recruiting more terrorists.

[…] Those who
claim that there was nobody before the war who doubted that Saddam
Hussein possessed WMDs which compelled our invasion ought to read this
passage from Dean’s speech:

Now, I am not among those who say that
America should never use its armed forces unilaterally. In some
circumstances, we have no choice. In Iraq, I would be prepared to go
ahead without further Security Council backing if it were clear the
threat posed to us by Saddam Hussein was imminent, and could neither be
contained nor deterred.

However, that case has not been made, and I believe we should continue the hard work of diplomacy and inspection. . . .

Secretary
Powell’s recent presentation at the UN showed the extent to which we
have Iraq under an audio and visual microscope. Given that, I was impressed not by the vastness of evidence presented by the Secretary, but rather by its sketchiness. . .

Can anyone dispute that Dean was right about
virtually every prediction and claim he made, every warning that he
issued about why invading Iraq was ill-advised and counter-productive?
Compare this outright prescience from Dean to the war supporters’
declarations of cakewalks, predictions of glorious victory
celebrations, promises that the war would pay for itself, Purple Finger
celebrations where they insisted that democracy was upon us, errors
regarding the number of troops needed, inexcusable failure to
anticipate or plan the insurgency, and shrill fear-mongering about
Saddam’s non-existent weapons.

Chalk one up for the left, I was prepared to think — against the Pentagon’s absurd faith-based mums and mints prediction, we in the reality-based community were right on.

Not so fast. I was astounded to come across this (h/t Wolcott):

With Iraq perched at the very precipice of an ethnic and sectarian
holocaust, the utter failure of the Bush administration’s policy is
revealed with starkest clarity. Iraq may or may not fall into the abyss
in the next few days and weeks, but what is no longer in doubt is who
is to blame: If Iraq is engulfed in civil war then Americans, Iraqis
and the international community must hold President Bush and Vice
President Cheney responsible for the destruction of Iraq.

The CIA, the State Department, members of Congress and countless
Middle East experts warned Bush and Cheney— to no avail— that toppling
Saddam could unleash the demons of civil war. They said so before the
war, during it and in the aftermath, and each time the warnings were
dismissed. Those warnings came from people like Paul Pillar, the CIA
veteran who served as the U.S. intelligence community’s chief Middle
East analyst, from Wayne White, the State Department’s chief
intelligence analyst on Iraq and from two CIA Baghdad station chiefs
who were purged for their analysis. Pillar, who wrote this month in Foreign Affairs that pre-war intelligence on Iraq was distorted by the Bush-Cheney team, is being excoriated by the right.

For the most radical-right neoconservative Jacobins amongst the
Bush-Cheney team, the possibility that Iraq might fall apart wasn’t
even alarming: they just didn’t care, and in their obsessive zeal to
overthrow Saddam Hussein they were more than willing to take the risk.
David Wurmser, who migrated from the Israeli-connected Washington
Institute on Near East Policy to the American Enterprise Institute to
the Pentagon’s Office of Special Plans to John Bolton’s arms control
shop at the State Department to Dick Cheney’s shadow National Security
Council in the Office of the Vice President from 2001 to 2006, wrote
during the 1990s that Iraq after Saddam was likely to descend into
violent tribal, ethnic and sectarian war.

In a paper for an Israeli think tank, the same think tank for which
Wurmser, Richard Perle and Douglas Feith prepared the famous “Clean
Break” paper in 1996, Wurmser wrote in 1997
: “The residual unity of the nation is an illusion projected by the
extreme repression of the state.” After Saddam, Iraq would “be ripped
apart by the politics of warlords, tribes, clans, sects, and key
families,” he wrote. “Underneath facades of unity enforced by state
repression, [Iraq’s] politics is defined primarily by tribalism,
sectarianism, and gang/clan-like competition.” Yet Wurmser explicitly
urged the United States and Israel to “expedite” such a collapse. “The
issue here is whether the West and Israel can construct a strategy for
limiting and expediting the chaotic collapse that will ensue in order
to move on to the task of creating a better circumstance.”

(As far as I can tell from skimming Wurmser’s paper, what he didn’t like about the then current situation was the nationalism of the Baathist rulers. Like many tories, his brow became dewy in the
presence of the our-class-dear hereditarily fancy; correspondingly his bizarre "Hashemite option" for expediting the chaotic collapse was to induce the royals of Jordan to woo clan leaders throughout the region, establishing a great big feudal-monarchic structure along the lines of mediaeval Britain: in other words, to restore the "natural" royalist system installed with great brutality by the Brits in the ’20s. So much for the Wilsonian rhetoric. As we now know, the Bush Gang had worked overtime with great care and delicacy prior to the invasion to bring this option about, by establishing the necessary diplomatic ties among the Hashemite clan bosses.)

Wow! So the leading war "planners" at the Pentagon themselves had no illusions about the inevitability of "chaotic collapse". The left from top to bottom, and the upper echelons of the right, were in total agreement! All the "peeance and freeance" rhetoric from the right was not just moronic drivel, but pure unadulterated bullshit. The only suckers here were the lumpen-right.

Memo to the lumpen-right: don’t get fooled again.