The news last week that a 21-year-old man from southeastern Massachusetts has been charged with giving away top-secret US military documents is unsettling. The accused, a member of our own Massachusetts Air National Guard, was stationed with the 102nd Intelligence Wing based at what used to be called Otis Air Force Base in Falmouth on Cape Cod.

As a young man, I, too, was a member of that Air National Guard squadron – the 102nd Tactical Fighter Wing, which has a changed mission some half a century later. Hearing of my old unit being the source of a major security breach was chilling to me and others who have proudly served in the unit.

The stories brought back some memories of my life in the Air Force’s ANG beginning in the fall of 1966 when the war in Vietnam was on and growing fast.

I was sworn into the Air Force in December 1966, underwent basic training in San Antonio, and took 30 weeks of schooling in aircraft electronics – “avionics” – at Keesler AFB in Biloxi, Mississippi. Then I returned home to the 102nd at Otis.

After seven months of training, I was expected to know how to diagnose and repair problems with the navigation and radio equipment of jet aircraft. It was as if someone had given me the keys to thefighter planes parked on the tarmac at Otis AFB. The pilots would go airborne each day, and this Airman First Class would climb into the cockpit and transmit a radio check.

“Tower, this is ANG 304- How Copy? Over.”

If all was okay, I’d release the aircraft; if a problem was spotted, I’d climb on the fuselage, unscrew about 60 dzus fasteners, uncouple, remove, and replace the black boxes with ones that worked, and remember to put the fuselage cover back on. Then, I’d turn the aircraft back over to the pilot.

Just a year earlier, I was trying to understand Chaucer and metaphysical poets. Now, as an enlisted Top Gun guy was about to go airborne, his successful mission was based entirely on my assurance that the radio and the NAVAIDs all worked.

The 102nd has a century-long and glorious history in serving our country. It was founded in 1921 on tidal flats at Jeffrey’s Point in East Boston, the site that later become Logan Airport. The unit grew and served in WWII with the 9th Air Force in France, then came home and settled back at Logan.

Reactivated as the 102nd National Guard unit in 1946, the squadron was called to active duty again during the Korean conflict. In 1961, when the Berlin Wall was built, 102nd airmen were sent for a year in France to provide air support for NATO’s US 7th army.

In 1968, the unit – then called the 102nd Tactical Fighter Wing – left Logan for good to settle in at Otis AFB, flying fighter aircraft, including F-84 and F-100 supersabres.

In 1972, it changed to the 102nd Air Force Defense Wing and transitioned to Mach 2 aircraft, the F-106 Delta Darts, with round-the-clock patrols over the East Coast that occasionally intercepted Soviet planes off Long Island. On Sept. 11, 2001, it was 102nd planes that chased after the terrorists who attacked the World Trade Center.

Combat aircraft patrol missions continued until 2008, when the fighter wing became an Intelligence Wing. It was this incarnation of the Air National Guard’s 102nd that broke into the headlines last week, when this young guy was revealed to be the source of the colossal leak in military secrets.

His case is a reminder that there have been generations of young men and women who have gone through brief periods of military training, and then were trusted to act with honor, valor, and great maturity. In this instance, apparently, a 21-year-old broke a sacred trust, one that we must be able to count on to keep our nation safe.