At first glance, the John Rambo trilogy appear to be just another series of explosion-packed action movies.

But there’s much more to them than napalm and machine guns.

Released at a time when we were still nursing divisive wounds from Vietnam, the movies struck a chord with many frustrated Americans. Rambo successfully played on the emotions of those who thought our government had bungled the whole Vietnam affair and had kept us from winning the war.

Rambo, as played by Sylvester Stallone, swings into action again with the release this week of “The Rambo Special Edition Trilogy DVD Collection” (Artisan, $59.99). The set includes all three Rambo films and a fourth disc contains seven featurettes and three documentaries many of them devoted to Vietnam, and to those who actually served there.

Americans were introduced to Rambo in “First Blood” (1982). An ex-Green Beret still haunted by memories of the war, Rambo drifts into a small Northwest town looking for a place to eat. Local sheriff Will Teasle spots the long-haired stranger and decides “we don’t need his kind around here.”

Teasle escorts Rambo out of town, a symbolic sequence that reflects the negative attitudes some Americans had toward Vietnam veterans at the time. When Rambo returns to town, Teasle arrests him and throws him in jail. Big mistake.

A confused and enraged Rambo escapes. With a posse in pursuit, he becomes an unstoppable one-man army and gives up only when his former commander, Col. Sam Trautman (Richard Crenna), arrives on the scene.

“Rambo: First Blood Part II” (1985) sends Rambo back to Vietnam in search of American POWs.

“Rambo III” (1988) finds Rambo going to Afghanistan in search of Trautman, who has been captured by Soviet forces.