The Iraqi defense minister said Monday that his nation would not be able to take full responsibility for its internal security until 2012, nor be able on its own to defend Iraq's borders from external threat until at least 2018.

Those comments from the minister, Abdul Qadir, were among the most specific public projections of a timeline for the American commitment in Iraq by officials in either Washington or Baghdad. And they suggested a longer commitment than either government had previously indicated.

Pentagon officials expressed no surprise at Qadir's projections, which were even less optimistic than those he made last year.

In remarks to the traveling press, delivered from the Third Army operation command center here, Bush said that negotiations were about to begin on a long-term strategic partnership with the Iraqi government modeled on the accords the United States has with Kuwait and many other countries. Crocker, who flew in from Baghdad with Petraeus to meet with the president, elaborated: "We're putting our team together now, making preparations in Washington," he told reporters. "The Iraqis are doing the same. And in the few weeks ahead, we would expect to get together to start this negotiating process." The target date for concluding the agreement is July, says Gen. Doug Lute, Bush's Iraq coordinator in the White House—in other words, just in time for the Democratic and Republican national conventions.

Most significant of all, the new partnership deal with Iraq, including a status of forces agreement that would then replace the existing Security Council mandate authorizing the presence of the U.S.-led multinational forces in Iraq, will become a sworn obligation for the next president. It will become just another piece of the complex global security framework involving a hundred or so countries with which Washington now has bilateral defense or security cooperation agreements. Last month, Sen. Hillary Clinton urged Bush not to commit to any such agreement without congressional approval. The president said nothing about that on Saturday, but Lute said last fall that the Iraqi agreement would not likely rise to the level of a formal treaty requiring Senate ratification. Even so, it would be difficult if not impossible for future presidents to unilaterally breach such a pact.

If the U.S. were to face a new conventional threat, its military could not respond effectively without turning to air power, officials and analysts say.

That is the ultimate upshot of the war in Iraq: a response elsewhere would consist largely of U.S. fighters and bombers — even, perhaps, some degree of nuclear strike — because so many ground troops are tied up in Operation Iraqi Freedom.

The New York Times found 121 cases in which veterans of Iraq and Afghanistan committed a killing in this country, or were charged with one, after their return from war. In many of those cases, combat trauma and the stress of deployment — along with alcohol abuse, family discord and other attendant problems — appear to have set the stage for a tragedy that was part destruction, part self-destruction.

Three-quarters of these veterans were still in the military at the time of the killing. More than half the killings involved guns, and the rest were stabbings, beatings, strangulations and bathtub drownings. Twenty-five offenders faced murder, manslaughter or homicide charges for fatal car crashes resulting from drunken, reckless or suicidal driving.

About a third of the victims were spouses, girlfriends, children or other relatives, among them 2-year-old Krisiauna Calaira Lewis, whose 20-year-old father slammed her against a wall when he was recuperating in Texas from a bombing near Falluja that blew off his foot and shook up his brain.