WASHINGTON—Iraq is about to become an unusual common ground for the presidential candidates, despite its divisiveness as a campaign issue. Sons of both vice presidential nominees are expected to arrive there soon to join the fighting.

Alaska Gov. Sarah Palin’s eldest son, Track, will perform security duties for his brigade’s top officers.

“He’s just like any other infantry soldier here,” said Army Col. Burt Thompson, who heads the 1st Stryker Brigade Combat Team at Fort Wainwright, Alaska. “He tries to remain as anonymous as he possibly can.”

Which is harder than it sounds.

When Sen. John McCain selected Track’s mother to be his running mate, the Alaska governor’s family moved into the international spotlight. She has made no secret that Track Palin and his unit are leaving soon for duty in Iraq, repeating the news during her acceptance speech this week at the Republican political convention. Track, in a dress suit, was in the audience.

The presidential campaigns remain deeply divided over how to end the contentious war—an issue that had front-burner status during the primary season but has not been quite so prominent recently. The deployments of Track Palin and Beau Biden, son of Democratic vice presidential nominee Joe Biden, make the subject an intensely personal one, nevertheless, for their families.

“They’re going to take a very keen interest in how that war is run,” said retired Army brigadier general David Grange. “It will affect their decision-making. No doubt about it.”

Beau Biden, who is Delaware’s attorney general, is a captain in the Delaware National Guard and will work as a military lawyer in Iraq.

John McCain’s son Jimmy, a Marine, returned earlier this year from Iraq. Another McCain son, Jack, is a senior at the U.S. Naval Academy.

Palin’s unit is believed to be headed to Diyala, among the most dangerous of Iraq’s 18 provinces. It extends from the northeastern suburbs of Baghdad to the Iranian border. Diyala has proven to be difficult to control because it is heavily mixed with Sunni Arabs, Shiite Arabs and Kurds.

Diyala was the fourth most violent of Iraq’s provinces, averaging more than 3.5 attacks each day, according to figures from June. It has not been returned to Iraqi control and probably won’t be before next year.

Citing security restrictions, the Army will not say where in Iraq Palin’s or Biden’s units are being sent. Both units are scheduled to be in Iraq for 12 months.

The British government pulled Prince Harry from Afghanistan earlier this year after news leaked he was fighting there. That sparked a debate about whether the children of powerful politicians are treated differently when they join the military.

Lt. Col. Len Gratteri, a spokesman for the Delaware Guard, said the only time special status for Beau Biden is discussed at the Guard’s headquarters in Wilmington is when the media calls to ask about him.

Palin’s job appears to be riskier than Biden’s.

Now 19, he enlisted last year and is assigned to the 1st Stryker Brigade’s Delta company. That’s Palin’s home state. The Army says his being posted in his home state was luck of the draw.

In military parlance, Palin is a “dismount.” He and other soldiers operate armored vehicles called Strykers. Their job is to ensure brigade commanders and their communications remain protected as they move around the country. The Stryker is an eight-wheeled truck that weighs 19 tons.

Gov. Palin said in her acceptance speech this week that her son’s unit will deploy to Iraq on Thursday. A deployment ceremony for the brigade takes place at Fort Wainwright then, but the route to Iraq is not a direct one. It will move in stages with stops in Kuwait for equipment.