In 1967, Martin Luther King Jr. spoke at Harlems Riverside Church to a crowd of thousands that flowed out the door as far as 120th Street. King publicly condemned the Vietnam War because it had broken and eviscerated the civil-rights and anti-poverty movements at home. The American government was the greatest purveyor of violence in the world today.

Read: Martin Luther King Jr. on the Vietnam War

In 2022, Ukrainian President Volodymyr Zelensky invoked another MLK speech while asking Congress to help his country repel the Russian invasion. I have a dream. These words are known to each of you today. I can say, I have a need: I need to protect our sky. Two months later, Democrats voted unanimously in favor of a $40 billion package of arms and other assistance to Kyiv.

These two moments capture an important shift in how the American left thinks about the U.S. military and war more generally. Progressives typically see war as inherently murderous and dehumanizingsapping progress, curtailing free expression, and channeling resources into the military-industrial complex. The left led the opposition to the Vietnam War and the Iraq War and condemned American war crimes from the My Lai massacre to Abu Ghraib. Historically, progressive critics have charged the military with a litany of sins, including discrimination against LGBTQ soldiers and a reliance on recruiting in poor communities.

Meanwhile, for decades, the right embraced Americas warriors. Defense hawks were one of the three legs of the Reagan stool, along with social and fiscal conservatives. The military itself leaned right. One study found that from 1976 to 1996, the number of Army officers who identified as Republican increased from one-third to two-thirds. In 2016, according to a poll in the Military Times, active service members favored Donald Trump over Hillary Clinton by a margin of nearly two to one.

In the past few years, however, these views have started to change. From 2021 to 2022, the share of Republicans who had a great deal or quite a lot of confidence in the military fell from 81 to 71 percent, whereas for Democrats, the number increased from 63 to 67 percentcutting the gap from 18 points to four. And the militarys views shifted in tandem. In 2020, dozens of former Republican national-security officials endorsed President Joe Biden because Trump had gravely damaged Americas role as a world leader. In one poll before the 2020 election, more active service members backed Biden than Trump (41 to 37 percent).

Why has this happened? Two big reasons are Trump and Ukraine.

Trump saw the military as a symbol of power and surrounded himself with a phalanx of generals. But when he realized they were not a Praetorian Guard that would do his bidding, defend him against all enemies foreign and domestic, and keep him in office by force if necessary, he soured on the military. Trump trampled on its most sacred beliefs and rituals, saying that U.S. generals were dopes and babies who want to do nothing but fight wars. Americans killed in battle, he said, were losers and suckers. Trump suggested that Gold Star families had spread COVID at the White House. He railed against American prisoners of war: I like people who werent captured. He pardoned three service members accused or convicted of war crimes, even though military leaders said it would erode the militarys code of justice. In his testimony to Congress, Trumps acting defense secretary, Christopher Miller, said that Trump had told him to ready the National Guard to protect his supporters on January 6, rather than Congress itself. All of this created a fundamental clash with the militarys code of honor and its commitment to the Constitution. Trump wondered why American generals couldnt be more like Hitlers generalsby which he meant the loyalist fanatics who battled in the ruins of Berlin, not the Wehrmacht officials who tried to assassinate the Nazi dictator.

Since he left office, Trump has fueled the conservative belief that Biden is indoctrinating the armed forces with liberal ideas. Republican Senator Ted Cruz said the U.S. military is suffering from a woke cancer and is in danger of becoming a bunch of pansies. The Fox News host Laura Ingraham suggested defunding the military until it abandons its diversity programs: Go after their budget.

Its true that the military has moved left, and not just because of Trump. After George Floyd was murdered in 2020, Kaleth Wright tweeted: Who am I? I am a Black man who happens to be Chief Master Sergeant of the Air Force. Last year the Pentagon warned, To keep the nation secure, we must tackle the existential threat of climate change.

This shouldnt be so surprising. The military is the epitome of big government, with egalitarian wages, socialized medicine, and the best government-run child-care system in the country. No wonder General Wesley Clark joked that its the purest application of socialism there is. Now progressives are expressing a new gratitude for an institution that understands the value of diversity, cares about the rule of law, and was willing to stand up to Trump when the future of democracy was most in danger. At a time of rampant conspiracy theories like QAnon, liberals appreciate that the military operates in a world of tangible threats and complex logistics and has a basic respect for reality. George Orwell said people often cling to falsehoods until the lie slams into the truth, usually on a battlefield.

Then came Russias invasion of Ukraine. No foreign conflict since the Spanish Civil War has so captured the imagination of the left. Nearly a century ago, many progressives saw Spain as a pure fight between democracy and fascism. Ernest Hemingways novel For Whom the Bell Tolls and Pablo Picassos painting Guernica captured the horror at fascist brutality. About 3,000 Americans traveled to Spain to fight in the international brigades. Today, many on the left see Ukraine as another contest between fascism and democracy, and that rare thing: a good war. Thousands of Americans have gone to join the struggle.

Russian President Vladimir Putin is the antithesis of everything the left stands for. Not only did he launch an unprovoked attack on a sovereign democratic nation, but he has also disparaged LGBTQ rights, multiculturalism, and immigration, and claimed that the liberal idea has outlived its purpose. Zelensky, in contrast, has built bridges with the global left. He addressed the Glastonbury music festival, in the U.K., where the revelers chanted his name to the tune of The White Stripes Seven Nation Army. In Germany, the Green Party led the charge to supply weapons to Kyiv, overturning decades of German wariness about intervening in foreign wars. LGBTQ protesters in Berlin also demanded that Germany step up arms shipments to Ukraine, so that a Pride parade can, one day, be held in the Russian-occupied city of Mariupol. Ukrainian liberalsartists, translators, teachers, filmmakershave joined the struggle. As one writer put it: All our hipsters in Ukraine fight.

To be sure, theres a leftist fringe in the United States that still considers America the worlds evil empire and remains deeply hostile to its military power. That fringe includes the linguist and political activist Noam Chomsky, who praised Trump as a model statesman for pushing for a negotiated peace in Ukraine. But the bulk of the left has shown remarkable solidarity with the Ukrainian cause. Liberals who once protested the Iraq War now urge Washington to dispatch more rocket launchers to defeat Russian imperialism. Representative Jamaal Bowman of New York, a member of the progressive caucus, tweeted: We unequivocally stand with the global Ukrainian community in the wake of Putins attack.

The main opposition to helping Ukraine has come from the right. Trump, who has long praised Putin as a genius, questioned why Americans were sending so much money to Ukraine. Most congressional Republicans backed the aid package to Kyiv in May, but 11 Republican senators and 57 House Republicans opposed it. Republican Representative Matt Gaetz tweeted that if the GOP takes the House in the upcoming midterms, support for Ukraine will end. The Fox News host Tucker Carlson claimed that Ukraine is an American puppet state, and that his real enemies are not in Moscow but on the American left: Has Putin ever called me a racist?

In March, Democrats were 10 points more likely than Republicans to say that Washington has a responsibility to protect and defend Ukraine from Russia. By July, this gap had grown to 22 points. Another recent survey found that Democrats were more supportive than Republicans of sending weapons to Ukraine as well as of accepting Ukrainian refugees in the United States. A remarkable 42 percent of Democrats favored deploying American troops to Ukraine, versus 34 percent of Republicans.

Progressives have always viewed foreign conflicts and domestic struggles as connectedwith war being either a dangerous contagion or a righteous crusade. A poster from the Spanish Civil War showed the image of a dead child: If you tolerate this, your children will be next. A generation later, the pendulum swung, and King saw intervention in Vietnam as a threat to civil rights in America. Today, the pendulum has swung back, and the left sees the march for freedom in America and the battle to defend Ukraine as elements of the same global fight for democracy. After all, the aggressor in UkrainePutinalso meddled in the 2016 election to help Trump.

Will the alliance between the left and the military last? Progressives may grow nervous about escalation in Ukraine or lose interest in the war. The economy remains the most pressing issue for most Americans. Perhaps, like Orwell in Catalonia, some American volunteers in Ukraine may decide that the struggle is not as pure as they thought. The lefts underlying concerns about the U.S. military have hardly disappeared. Republicans may one day shove Trump offstage and try to get the 80s band back togetherdefense hawks, social conservatives, and fiscal conservatives.

But for now, Trump remains the dominant force in the Republican Party. The Ukrainian cause remains resonant. And the left may worry about another authoritarian great power that threatens a smaller democracy: China mobilizing against Taiwan.

An era of liberal hawkishness should not mean an unthinking embrace of the military. America needs a strong progressive voice to check the rampant waste in the military-industrial complex (which ran to hundreds of billions of dollars in Iraq and Afghanistan). The military has very real problems, like the crisis of sexual assault. It doesnt benefit from the sort of soft-focus Thank you for your service reverence that has prevented people from asking tough questions about Americas disastrous wars in the past. On Ukraine, liberals can channel Washingtons policy in a more progressive direction, stressing human rights, pressing for investment in green technology to reduce reliance on Russian energy, and going after Moscows dirty money.

In the end, the U.S. military is the worlds anti-fascist insurance policy. The insurance premiums may be outlandish. And most of the time we dont need the policy. Until one day we do. If you need to ship M777 howitzers to Ukraine, the military-industrial complex has its uses.

In 1967, King was right to see Vietnam as a catastrophe for America, at home and abroad. If Americas soul becomes totally poisoned, part of the autopsy must read: Vietnam. But today we face a different world, and a stark choice. Zelensky, Ukrainian progressives, and the European Union? Or Putin, Trump, and Tucker Carlson? The left picked the right side.

Read more:

Why the Left Is Learning to Love the Military - The Atlantic