His wife, Gail Huff, raced to meet him in a crowded terminal at Logan International Airport. Photographers captured their kiss and long embrace.

The scene has played out across Massachusetts countless times during the past decade as Guard units have returned from deployments in Iraq and Afghanistan.

Brown, though, returned not as a veteran of a protracted period of duty but after a 14-day Army National Guard assign­ment he requested. During that span, he spent seven days in Afghanistan itself.

While there, he participated in training exercises with the troops, but he also spent considerable time meeting with generals, ambassadors, and other leaders, an experience more akin to his role as US senator.

A picture of his reunion with Huff subsequently appeared in Brown’s reelection announcement video and reappeared in a television ad and web video.

And during his latest debate with Democratic challenger Elizabeth Warren Wednesday night, Brown noted that he “served in Afghanistan” as he protested potential cuts in military spending.

During his 32 years of Guard service, which started long ­before he entered the halls of government, Brown has established a strong record bolstered by consistently high officer evaluations.

But since being elected to the Senate in 2010, his service has taken on a political patina, with the Guard providing him unusual opportunities that he has used as fodder for his campaign, as well as the flexibility necessary to participate in one of the country’s most hotly contested elections.

As citizen-soldiers, all Guardsmen are required to serve one weekend a month and two weeks each summer.

In 2011, Brown was granted a request to fulfill his summer training commitment in ­Afghanistan, sending him to a combat zone for the first time in his military career just as his reelection campaign was ramping up.

This year, with the election in full gear, Brown was in a ­position to serve his summer duty in a piecemeal fashion, in single days spread beyond just the summer months, allowing him to avoid an extended ­absence from the campaign trail.

The two days he was known to have served in August coincided with the start of the ­Republican National Convention, the type of overtly partisan event he has avoided as he runs against Warren in what ­remains heavily Democratic Massachusetts.

In the past two years, the senator has also won a much-coveted promotion to colonel, one notch below general.

He secured it after a surprising transfer to the Maryland National Guard. Veteran ­observers of the Maryland Guard say it is the first time the state’s main judge advocate general corps, the military’s equivalent of a law firm, has had four colonels attached to it. Military manning documents authorize it for one.

At the same time, Brown ­began working out of the ­Pentagon, as assistant to the chief legal counsel for the ­National Guard Bureau, serving in the same office complex as the top general overseeing the Guard. These are the same people and the same agency Brown helps oversee as the ranking member, or top Republican, on the Senate Armed Services subcommittee with jurisdiction over the National Guard.

Brown’s dual roles and transfer have created a rare phenomenon: a US senator from Massachusetts sworn as a military officer to uphold the constitution of Maryland and, should the need arise, to take orders from Governor Martin O’Malley of Maryland.

Brown’s uniform bears a Guard emblem for Maryland, a state where he does not live, work, or fulfill his duty.

Since his upset victory in a January 2010 special election to fill the seat that had been held by the late Senator Edward M. Kennedy, Brown has made it clear how central his Guard service has been both to his legislative agenda and reelection ­efforts.

The day the senator ­returned from Afghanistan, he called on Congress to support his legislation making it easier for US officials to break contracts with businesses caught funneling taxpayer resources to US enemies.

He also has organized job fairs for veterans returning from Iraq and Afghanistan, and filed what was known as the Stolen Valor Act to penalize those who might lie about their military records.