President Obama announced today that all U.S. troops would be gone from Iraq by the year’s end. The Post reported:

The Obama administration has decided to withdraw all U.S. forces from Iraq by the end of the year after failing to reach an agreement with the Iraqi government that would have left several thousand troops there for special operations and training. . . The two leaders also agreed to continue informally discussing the need for and the terms of a U.S. military presence in Iraq into next year, people familiar with the agreement said. As a result, the only U.S. military presence that will remain in Iraq after the end of the year will be the roughly 150 troops needed to protect the large U.S. Embassy compound in Baghdad and its thousands of American diplomats and other personnel, as well as provide training related to new military sales and other tasks.

In other words, due to the failure of Obama diplomacy, we will leave Iraq essentially on its own in about two months. Obama was plainly pleased with himself. “The last American soldiers will cross the border out of Iraq with their heads held high, proud of their success and knowing that the American people stand united in their support for our troops. That is how America’s military efforts in Iraq will end.” He couldn’t manage to utter the word “victory,” but “success” (as he and his National Security Council adviser put it) in the war Obama strenuously opposed can no longer be denied.

Conservative critics, however, are not pleased with the abrupt departure. Former U.N. ambassador John Bolton tells me: “Obviously, we would never stay in Iraq without the consent of the government, but we have badly bungled this stage of the relationship, starting in the Bush Administration with the 2008 agreement that set the December 31, 2011 date.” He said we should have seen this coming. “Obama’s own decision was really made the day he took office, and it is intensely political and ideological rather than strategic. He wanted out, and now he has what he wanted. So while part of the responsibility rests with the prior Administration, the bulk of the blame for the harm that will now befall our interests in Iraq and the region will be Obama’s.”

Fred Kagan, a key strategist in the war was livid. He posted the following:

President Obama announced today that he has decided to abandon America’s interest in Iraq and damage our position in the Middle East by withdrawing all US military forces by the end of this year. This retreat will have great costs for the U.S. It squanders the gains made by both American and Iraqi military forces over the last four years, but, even more important, it squanders the enormous opportunity to forge an alliance with Iraq at a time when such an alliance would be of tremendous value to the US. It dramatically increases the likelihood that the new and unstable Iraqi democratic experiment — already under attack from an authoritarian Prime Minister and a hostile Islamic Republic of Iran — will fail. The withdrawal of American forces now serving as peacekeepers along the Arab-Kurd seam greatly increases the likelihood of ethnic civil war. The withdrawal of American military protection from a state helpless to defend itself on its own effectively throws Iraq into the arms of Iran, however the Iraqis feel about the matter.

It makes a mockery, moreover, of the notion that the US is somehow isolating Iran and increasing the pressure on the Islamic Republic mere days after the revelation of an elaborate Iranian plot to conduct attacks on American soil. What sort of sanctions regime can we maintain if Iraq is effectively a free-trade corridor with Iran? How can we argue that Iran is being isolated when its ability to operate terror groups and training areas within Iraq is growing unchecked? How can we claim to be taking a firm line against Iran while giving Tehran the single most important demand it has pursued for years — the complete withdrawal of US military forces from Iraq? There is no benefit to the United States from this unnecessary decision, and likely much loss.

Other conservative defenders of the war are also worried. Gary Schmitt of the American Enterprise Institute e-mailed me, “As best anyone can tell, the administration is at the end of the day willing to settle for containing and deterring a nuclear-capable Iran. So, what better place to be in than next door in Iraq? If for no other reason than this, leaving Iraq is strategically incoherent.” Schmitt’s colleague Thomas Donnelly has a similar reaction: “Geopolitically, it’s a terrible move, reinforcing the growing belief that America is in decline and retreat. Strategically, it mocks the idea of any long-term partnership with Iraq and marks a major concession to Iran. Militarily, a retreat from what was a painful but significant. But it is also a measure of our domestic politics. The president continues his leftward move — this is of a piece with his embrace of ‘Occupy Wall Street’ and tax-the-rich ploys. And it begs the question of the opposition: will the Republican candidates repudiate this?”

Mitt Romney put out a brief statement criticizing Obama: “President Obama’s astonishing failure to secure an orderly transition in Iraq has unnecessarily put at risk the victories that were won through the blood and sacrifice of thousands of American men and women. The unavoidable question is whether this decision is the result of a naked political calculation or simply sheer ineptitude in negotiations with the Iraqi government. The American people deserve to hear the recommendations that were made by our military commanders in Iraq.” As of this writing, other campaigns had not put out statements.

The Foreign Policy Initiative co-founded by three key defenders of the Iraq war (Bill Kristol, Robert Kagan and Dan Senor, an informal adviser to the Romney campaign) put out a fact sheet identifying its concerns. It read in part:

Given that Iraqi Security Forces still heavily rely on American capabilities for logistics, intelligence gathering, and naval and airspace defense, if the United States does not leave adequate forces in Iraq, it will leave Iraq more vulnerable to internal and external threats, thus imperiling the hard-fought gains in security and governance made there in recent years. It is also essential that the U.S. military maintain a significant troop presence at multiple places along Iraq’s “disputed internal boundaries” to allow the United States to assist Kurds and Arabs in the disputed zones with confidence-building.

A letter signed by a who’s-who of conservative foreign policy hawks was also sent to the president. It read:

Dear President Obama:

The United States has invested significant resources in Iraq over the last eight years. Under your leadership and that of your predecessor, America has helped Iraq’s fledgling democracy emerge as a symbol to other peoples of the region, becoming, in the words of former Secretary of Defense Gates, “a multi-sectarian, multi-ethnic society in the Arab world that shows that democracy can work.”

We are thus gravely concerned about recent news reports suggesting that the White House is considering leaving only a residual force of 4,000 or fewer U.S. troops in Iraq after the end of this year. This number is significantly smaller than what U.S. military commanders on the ground have reportedly recommended and would limit our ability to ensure that Iraq remains stable and free from significant foreign influence in the years to come.

While the Iraqi Security Forces have become increasingly capable of defending Iraq against internal threats, they are not yet able to defend Iraq from external forces. As a result, Iraq’s troops will require after the end of this year continued U.S. assistance in combined-arms training, border protection, air and naval capabilities, logistics, and intelligence. It is also essential that we maintain a significant military presence at multiple places along Iraq’s disputed internal boundaries to allow the United States to assist Kurds and Arabs in the disputed zones with confidence-building.

In recent months, Iran has increased its attempts to expand its influence in Iraq, including through the killing of American forces and support to Iraqi political parties. Maintaining a robust American presence in-country would blunt these efforts, and help ensure Iraq remains oriented away from Iran and a long-term ally of the United States.

We therefore urge you to ensure that an adequate number of U.S. troops in Iraq remain after 2011. We were encouraged by your pragmatism in 2009 as you showed flexibility in the pace of America’s drawdown. We believe that the same pragmatism would counsel a significantly larger force than 4,000 U.S. troops in Iraq after the end of this year.

Failure to leave a significant U.S. military presence in Iraq will leave the country more vulnerable to internal and external threats, thus imperiling the hard-fought gains in security and governance made in recent years at significant cost to the United States. A successful, democratic Iraq will remain a model for other emerging Arab democracies and one day, its neighbor, Iran. However, a failing state in the heart of the Middle East would destabilize the region, empower Iran, and make vain more than eight years of efforts by the United States in Iraq.

You have fulfilled your campaign commitment to the nation to end the war in Iraq. Now, we request that you ensure that in doing so, we do not lose the peace.

Should Iraq’s tenuous peace unravel, Obama will have a foreign policy debacle on his hands. More to the point, when combined with our lackluster approach to Iran (ignoring the failure of sanctions to halt its program, quietude on human rights), we are emboldening, once again, the mullahs. Our allies in the region have good reason to view us as unreliable.

UPDATE (4:10 p.m.): A Herman Cain spokesman emails me: “We are concerned that the complete withdrawal of US troops from Iraq, according to the Obama Administration’s politically-driven timetable, will leave a power vacuum that Iran will readily exploit. We owe it to the thousands of US servicemen who lost their lives in Iraq to ensure that their ultimate sacrifice has made a lasting impact in creating a stable, free and prosperous country for all Iraqis. Telling the enemy when we are going to leave is not good policy.”

UPDATE II (5:10 p.m.): Rep. Michele Bachmann (R-Minn.) issued this statement: “Today’s announcement that we will remove all of our forces from Iraq is a political decision and not a military one; it represents the complete failure of President Obama to secure an agreement with Iraq for our troops to remain there to preserve the peace and demonstrates how far our foreign policy leadership has fallen. In every case where the United States has liberated a people from dictatorial rule, we have kept troops in that country to ensure a peaceful transition and to protect fragile growing democracies. We will now have fewer troops in Iraq than we have in Honduras – despite a costly and protracted war. President Obama’s decision represents the end of the era of America’s influence in Iraq and the strengthening of Iran’s influence in Iraq with no plan to counter that influence. We have been ejected from a country by the people that we liberated and that the United States paid for with precious blood and treasure. The administration claims that we got exactly what we needed, but today’s announcement demonstrates otherwise. The United States needed a working democratic partnership in Iraq and we should have demanded that Iraq repay the full cost of liberating them given their rich oil revenues. I call on the president to return to the negotiating table with Iraq and lead from the front and not from weakness in Iraq and in the world.”