Iraq week, I predict, will prove to have been a good one for at least two of the New Yorkers who are maneuvering for the presidency — and maybe for all three.

Let’s start with Senator Clinton. On September 10, she refused to condemn the MoveOn.org ad that accused General Petraeus of betraying his oath of service and cooking the books for President Bush’s war. On September 11, she winged down from ground zero to the Senate Foreign Relations Committee and told the freshly defamed general that his assessment of the war in Iraq required the “willing suspension of disbelief,” a fancy way of calling him a liar.

This performance earned her three fortuitous days of sustained bashing from Mayor Giuliani, who demanded she apologize to the commander leading our troops in battle. For a Democratic candidate who not only voted to authorize the toppling of Saddam Hussein, but scolded the earnest protestors at Code Pink when they questioned her vote, what could be better than having a pro-victory Republican say she was too tough on the military?

To understand how much the mayor’s advertisement in Friday’s New York Times is helping the senator, imagine that the National Association for the Repeal of Abortion Laws ran television spots in South Carolina for the Republican primary warning voters that President Giuliani would stack the Supreme Court with pro-life justices.

The typical New York Times reader agrees with that paper’s editorial board, moveon.org, and Mrs. Clinton — there is no way any objective observer could report progress of any kind in Iraq. Here you have a bogeyman confirm your strength on an issue where the base thinks you waiver. With enemies like that, who needs friends?

But just as Mr. Giuliani benefits Mrs. Clinton, the reverse is also true. Call it a strategy of mutually assured nomination. For the September 11 mayor, the sixth anniversary of the outbreak of the war could have been politically disappointing. He spent most of the day at the Freedom Concert in New Jersey with Sean Hannity, raising his profile with the base but away from the glare of the national press.

The printing press and broadcast operators were focused on Washington and Iraq. While it’s probably still too early to predict, most polls show Mr. Giuliani is the national frontrunner, but he lags behind in New Hampshire and Iowa. On top of this, Senator Thompson, the former senator from Tennessee, has just entered the race to save American conservatism from the compromise conservatives who have been running for nearly a year.

For Mr. Giuliani to distinguish himself in this field, he has to make sure that the war against international Jihad is not only an important primary issue, but the hottest primary issue. If Republicans start talking to themselves about guns, babies, marriage, or day laborers, the 9-11 mayor can’t even say, “Me too.” Lo and behold, here fetches up the former first lady that he almost ran against in 2000 trashing the integrity of a four star general. It’s enough to make you wonder if the former mayor sent the senator a dozen roses before he pounced.

The fact that Mrs. Clinton and Mr. Giuliani are in a squabble before the first votes in Iowa and New Hampshire are cast makes both seem more presidential. For Republicans, Mr. Giuliani appears above the fray, attacking the likely nominee instead of the credentials of his challengers in strict accordance with Reagan’s 11th amendment (attack no Republican). For the Democrats, Hillary can employ the same line her husband used in 1992 — the only reason the wing-nuts are attacking me is because they don’t want to run against me.

For all their differences they are similar. Both have sought to carve out a middle ground on the values issues. Mrs. Clinton has pointedly said that there are too many abortions, but that she would like to keep them safe and legal. Mr. Giuliani dressed up as a woman for Saturday Night Live and lived for a while with a Gay couple. While Hillary certainly appears to be embracing retreat in the Battle of Iraq, not to mention a hard left contempt for the military, she has been quite vocal about how America must make a long-term military commitment to protect the Kurds, and until she reversed course she was one of the first Democrats to acknowledge the military gains in Anbar.

How these New Yorkers campaign defines them more than the positions they have taken in the past. But this week’s spat over General Petraeus — a man who could challenge either of them in 2012 if he wins the war for Iraq — also tells us a lot about the two major parties. Democrats are so determined that America and Iraq lose Bush’s war that they insist that anyone who says otherwise is a liar.

Because of the Democratic party’s radical crouch, Republicans have made the shooting war abroad more important than the culture war at home. Why else would Mr. Giuliani still be leading the national polls? Meanwhile both New Yorkers need each other to make the case to their respective primary voters. And if either strays to far to the extreme, there’s at least a chance a third New Yorker — Mayor Bloomberg — will try to make an end-run right down the middle.