The tactic of “salting” — getting a job with the specific intention of organizing your workplace — has recently been grabbing news headlines.

In a recent Bloomberg story, labor journalist Josh Eidelson showed how the Starbucks union drive, which began in Western New York and continues across the country, was started by salts. Eidelson, as well as labor journalist Luis Feliz Leon and scholar Mie Inouye, emphasized the critical role salts also played in the successful Amazon union drive in Staten Island. During recent Senate hearings on union busting at Starbucks, ex-CEO Howard Schultz referred to salting as a “nefarious act,” and industry groups are backing Republican efforts to crack down on the practice.

Salting helped build the labor movement over the past century and is clearly making a comeback in the new surge of union organizing. Right now, there are likely hundreds, if not thousands, of salts or salts-in-training who are driving new organizing efforts that will surface in the months and years ahead.

But while the tactic of salting in the workplace is getting attention, much less well known is the crucial role that salting played in building antiwar resistance in the US military during the Vietnam War.

From the mid-1960s through the mid-1970s, dozens of left-wing organizers entered the armed forces with the explicit intention of organizing antiwar resistance within the ranks. Some of them adamantly enlisted, but many were drafted and then decided to report to induction with the goal of talking to fellow GIs about the war, imperialism, and racism. Some were secretive about their military salting, while others were bolder and more open. Many soldiers who were politicized after entering the military were influenced by GI salts.

These GI salts played a crucial role in kickstarting and sustaining the massive wave of soldier protest during the Vietnam War. They established some of the most high-profile GI antiwar groups and drove some of the most notable cases of troop dissent, providing inspiring models for thousands of other servicemembers who doubted the war. They helped convert latent troop discontent into organized resistance. These were the “militant minority” of antiwar GIs, with radical visions of peace and equality, willing to take risks against military authority because they were driven by a higher mission to end the war.

The GI movement against the US war in Vietnam involved thousands of active-duty soldiers and threw the US military into crisis. It may have been the cutting edge of the wider antiwar movement. Yet, the history of the GI movement is little known to many.