Fifty years ago today, millions of Americans joined epic anti-war protests in Washington, DC, and across the United States. Organized by young activists who had cut their teeth on the peace politics of the 1968 Democratic primary between candidates Eugene McCarthy and Robert F. Kennedy, the October 15, 1969, Moratorium to End the War in Vietnam took the movement back to the streets for mass demonstrations, as students activists joined newly formed “Veterans for Peace” chapters, civil rights activists, migrant farmworkers, CEOs, and socialists to declare that it was time to give peace a chance.

The Moratorium was everywhere, from the steps of the Douglas County Courthouse in Omaha, Nebraska, to Trinity Church at the head of Wall Street in New York City. In Washington, a quarter-million Americans joined in a candlelight march from the Lincoln Memorial to the White House. They were led by Coretta Scott King, who hailed the nonviolent protests as a continuation of the campaigning of her late husband, the Rev. Martin Luther King Jr., for an end to the war that had diverted so much energy and so many resources from the struggle for economic and social justice at home.

It is by chance that the 50th anniversary of the Moratorium falls this year on the same day as the fourth round of Democratic presidential debates. Today’s Democratic Party leadership is neither so historically inclined nor so prescient to have timed a debate with an eye toward highlighting the contribution of peace movements and peace candidates.

This Democratic Party is different from the one that rejected its anti-war contenders in 1968. But it’s still a party that struggles to define itself when it comes to questions of war and peace, interventions abroad, and bloated military budgets. That’s just one reason it makes sense to demand what we will not get tonight: a debate focused exclusively on issues of war and peace, militarism and imperialism, instead of anecdotal discussions that touch on a past vote or the latest crisis created by President Trump, Democrats need to have a full and robust debate on these issues and issues like them.

I have argued before and will keep arguing that the Democrats should schedule an issue-focused debate on the climate crisis. It is absurd for the candidates to refer to climate change as the existential crisis of our time and yet hold debates in which the crisis is discussed for a few minutes on the way to another review of where the candidates stand on the issues they have already pontificated upon.

The climate debate deserves its own debate night because it’s about the future of our species. The war-and-peace debate deserves its own night for the same reason.

Anyone who doubts this should pause and consider the complex questions that have arisen since President Trump ordered US troops to leave northern Syria, giving Turkey the green light to attack the Kurds and create violent chaos that extends with each passing day. Should the United States have had troops in Syria in the first place? Why were those troops dispatched to Syria without a formal congressional debate and declaration of war? And what responsibility does a president have—once troops have been sent into a conflict zone and alliances have been formed—to end the deployment thoughtfully and ethically?

Now, multiply those questions out to cover all the regions of the world to which US troops have been deployed. Start asking about all the expenses—human, diplomatic, and economic—that result from those deployments. And get a simple “yes” or “no” from each presidential candidate on whether they agree with Representative Ro Rhanna when he says that “Congress decides when we go to war. That is a fundamental aspect of our system of checks and balances.”

It is clear that there are more than enough topics for what would be much more than a single-issue debate. It would pin down former vice president Joe Biden, who seems to be a bit confused about the meaning (and lasting consequences) of his vote to authorize the Iraq invasion. That’s just one of the issues Biden needs to more thoroughly address.

But it’s not just about Biden. A war-and-peace debate would give candidates who have thought these issues through a chance to shine—and to help advance the conversation. I’ve talked with a number of the contenders about war-and-peace issues and, frankly, I’ve been impressed. Vermont Senator Bernie Sanders is right when he says, “We need to rethink the militaristic approach that has undermined the United States’ moral authority, caused allies to question our ability to lead, drained our tax coffers, and corroded our own democracy.”

So, too, is Massachusetts Senator Elizabeth Warren, who made a lot of sense in September when she told the Council on Foreign Relations, “Our repeated mistake has been to ignore the relationship between a strong and vibrant America and our effectiveness at advancing our interests abroad. By treating foreign policy as separate from domestic policy, we have repeatedly misspent our strength overseas while leaving vital needs at home unattended. We have the world’s largest economy but have failed to pursue foreign policies that prioritize American workers. We have the world’s strongest military, but we fight too many wars.”

Representative Tulsi Gabbard has pulled no punches with her declaration that “our leaders have failed us—wasting trillions of dollars and countless lives in regime change wars and new cold war, bringing us ever closer to nuclear annihilation. As president, I will end this insanity.” And when I interviewed former representative Beto O’Rourke, I was struck by his deep understanding of the blowback the United States has suffered from past interventions in Iran, Guatemala, El Salvador, Iraq, and other countries. He got to the heart of the matter when he said, “Tell me that any of those wars or covert actions or interventions have made those countries, the world, or our foreign-policy prospects any better. They haven’t.”

A lot of the signals that are being sent by these candidates are good. But it is one thing to present a position paper or answer a few questions. It is something else altogether to debate the issues, to identify differences between the contenders and to see how comfortable the candidates are with these issues. That’s a debate that the Democrats need to have.