For decades, I kept a poster on my wall that I’d saved from the year I turned 16. In its upper left-hand corner was a black-and-white photo of a white man in a grey suit. Before him spread a cobblestone plaza. All you could see were the man and the stones. Its caption read, “He stood up alone and something happened.”

It was 1968. “He” was Minnesota Senator Eugene McCarthy. As that campaign slogan suggested, his strong second-place showing in the Maine primary was proof that opposition to the Vietnam War had finally become a viable platform for a Democratic candidate for president. I volunteered in McCarthy’s campaign office that year. My memory of my duties is now vague, but they mainly involved alphabetizing and filing index cards containing information about the senator’s supporters. (Remember, this was the age before there was a computer in every pocket, let alone social media and micro-targeting.)

Running against the Vietnam War, McCarthy was challenging then-President Lyndon Johnson in the Democratic primaries. After McCarthy had a strong second-place showing in Maine, New York Senator Robert F. Kennedy entered the race, too, running against the very war his brother, President John F. Kennedy, had bequeathed to Johnson when he was assassinated. Soon, Johnson would withdraw from the campaign, announcing in a televised national address that he wouldn’t run for another term.

With his good looks and family name, Bobby Kennedy appeared to have a real chance for the nomination when, on June 5, 1968, during a campaign event in Los Angeles, he, like his brother, was assassinated. That left the war’s opponents without a viable candidate for the nomination. Outside the Democratic Party convention in Chicago that August, tens of thousands of angry, mostly young Americans demonstrated their frustration with the war and the party’s refusal to take a stand against it. In what was generally recognized as a police riot, the Chicago PD beat protesters and journalists bloody on national TV, as participants chanted, “The whole world is watching.” And indeed, it was.

In the end, the nomination went to Johnson’s vice president and war supporter Hubert Humphrey, who would face Republican hawk Richard Nixon that November. The war’s opponents watched in frustration as the two major parties closed ranks, cementing their post-World-War-II bipartisan agreement to use military power to enforce U.S. global dominance.

Of course, the McCarthy campaign’s slogan was wrong on two counts. He didn’t stand up alone. Millions of us around the world were then working to end the war in Vietnam. Sadly, nothing conclusive happened as a result of his campaign. Nixon went on to win the 1968 general election and the Vietnam War dragged on to an ignominious U.S. defeat seven years later.

Nineteen sixty-eight was also the year my high school put on Tiger at the Gates, French playwright Jean Giraudoux’s antiwar drama about the run-up to the Trojan War. Giraudoux chronicled that ancient conflict’s painful inevitability, despite the fervent desire of Troy’s rulers and its people to prevent it. The play opens as Andromache, wife of the doomed Trojan warrior Hector, tells her sister-in-law Cassandra, “There’s not going to be a Trojan war.”

Cassandra, you may remember, bore a double curse from the gods: yes, she could see into the future, but no one would believe her predictions. She informs Andromache that she’s wrong; that, like a tiger pacing outside the city’s walls, war with all its bloody pain is preparing to spring. And, of course, she’s right. Part of the play’s message is that Cassandra doesn’t need her supernatural gift to predict the future. She can guess what will happen simply because she understands the relentless forces driving her city to war: the poets who need tragedies to chronicle; the would-be heroes who desire glory; the rulers caught in the inertia of tradition.