More than 300 people marched through downtown Denver in protest of the Trump administration's escalation of a conflict with Iran.

When a coalition of anti-war groups made plans for a rally at the Colorado State Capitol late last month, they expected a relatively small protest over an issue that had gone largely overlooked: the growing U.S. military presence in Iraq and the Middle East amid rising tensions with Iran.

Then, just after the New Year, President Donald Trump ordered the conflict’s most dramatic escalation yet, a drone strike that killed a top Iranian military official and sparked fears of an all-out war. Protesters in more than seventy cities took to the streets on Saturday, January 4, to demand an end to the conflict and the withdrawal of U.S. troops from the Middle East.

By the time demonstrators left a short rally at the Colorado State Capitol to march through downtown Denver, more than 300 people had joined the protest — far more than organizers had expected.

“It really speaks to how unbelievable the actions by the Trump administration were,” says Ryan Hamby, an activist with the Act Now to Stop War and End Racism (ANSWER) Coalition. “People are shocked.”

Tensions between the U.S. and Iran have been steadily rising since Trump’s 2018 decision to withdraw from the Joint Comprehensive Plan of Action, an agreement on limiting Iran’s nuclear program reached by its leaders, the Obama administration and several other major world powers in 2015. A series of escalations from both countries has followed, including the imposition of harsh new sanctions by the Trump administration, Iran’s shooting down of a U.S. surveillance drone, and a violent protest at the U.S. Embassy in Baghdad by Iranian-backed militias.

The January 2 killing of Iranian General Qassem Soleimani, however, has propelled the conflict into dangerous new territory, with Iran vowing "severe revenge" and many, including millions of Iraqis, fearing where further hostilities could lead. The Trump administration and its allies, including Colorado Republican Senator Cory Gardner, have claimed that Soleimani's killing was necessary to prevent an "imminent attack" on the U.S., but they have provided no substantiation for those claims, and officials quoted by the New York Times describe the evidence as "razor thin" and an "illogical leap."

“This is what the U.S. does, over and over again, all around the world,” Hamby says. “They think they can act with impunity. The U.S. has been at war since I have been alive, and really since the country came into existence.”

Demonstrators and speakers at the January 4 rally in Denver repeatedly expressed frustration not only with Trump and Republicans, but also with Democrats who they charge aren't delivering a true anti-war message. While Senator Michael Bennet, a candidate for his party’s 2020 presidential nomination, called the strike a “terribly reckless and provocative act,” other Colorado Democrats offered only muted and indirect criticism of Trump's actions. Former governor and Democratic Senate frontrunner John Hickenlooper, for example, released a short statement saying only that "we shed no tears" for Soleimani's death and calling for a "clear strategy" to deal with the fallout.

"The real anti-war movement is in the streets," says Hamby. "What we need is to bring more people out into the streets like we're seeing right now, and show that people oppose war."

Jake Altinger, a former U.S. Army Ranger who was deployed to Afghanistan three times, was one of those people. He marched with other anti-war veterans because, he says, it's "terrifying" to see the country on the verge of repeating the mistake it made in going to war in Iraq.

"We were lied to when we were sent to war in Iraq and Afghanistan," adds Altinger. "I joined the Army right out of high school, and I believed all the lies that we were told about Iraq — that we were fighting evil Islamic terrorism and we were going to take out a dictator with weapons of mass destruction. And it was all lies."

As they rallied and marched from the Capitol to Union Station, protesters encountered a few hecklers, including one woman who shouted at them to "support your country." Altinger and his fellow veterans say that by trying to prevent another costly, deadly war in the Middle East, that's exactly what they're doing.

"There couldn't be anything more un-American than simply going along uncritically with whatever your government says," Altinger says.

Amid global fears about what might come next, at least 3,500 additional U.S. troops have been ordered to the region, and on January 4 Trump warned Iran that any retaliation for Soleimani's killing would lead to further escalation by the U.S., including a threat to destroy Iranian cultural sites — which, according to international law, would be a war crime. Activists say they'll continue to protest and send an aggressively anti-war message to Trump, Democrats and the world.

“I feel shocked, I feel afraid, I feel horrified, but I feel hopeful seeing the amount of people that came out here," Hamby says.