They started chanting as I stood up: “Fire Chief Suhr!”

In my first act as western director for Iraq and Afghanistan Veterans of America, I was invited to lead the Pledge of Allegiance at Mayor Ed Lee’s inauguration. As I climbed the steps of the rotunda, the protesters grew louder, trying to stop the ceremony.

Like the protesters and the audience, I’m concerned about disparity, I too believe black lives matter, and I also hold that protest is patriotic. But I was here to do the job I was asked to do.

When I helped start IAVA in 2004, there was shouting, too. As a veteran in San Francisco, you’re often the only vet that folks know. Only 1 percent of my peers have served, and most of my friends opposed the war in Iraq. When IAVA represented veterans, we were welcomed. But if discussion turned to war or then-President George W. Bush, things got loud.

The irony was that I also opposed the war. But I took an oath to uphold the Constitution. When Congress voted, I registered my opposition with my representative, deferred to the majority, and did my duty professionally and compassionately. Participation in civil society means you don’t always get your way. But when I came home I helped create an organization that would help Americans make better decisions about war and connect with and empower veterans.

This election has left San Francisco feeling divided. Progressive renters in the city center are angry about the growing disparity and skyrocketing rents of the tech boom. They’re surrounded by working-class immigrants who are more moderate; blacks; and homeowners who re-elected the city’s first Asian American mayor. These progressive activists, together with supporters of the Black Lives Matter movement, were protesting the shooting of Mario Woods and the inauguration of Mayor Lee.

I waited, allowing the protesters to be heard. Then I placed my hand over my heart and began the pledge.

My words were barely audible, but the audience in the rotunda joined and our voices merged with the protest raining from the balcony. For that moment, with one cacophonous voice singing conflicting songs, we did America together.

Protest is patriotic. But it’s not enough. San Francisco is a city of makers and doers. We’re enthusiastic critics, but we know that solutions mean doing something new. Together. Protest can highlight problems, but it will ultimately require the best of the city’s progressives working within the system and enacting smart policy to successfully address disparity and housing affordability in the city. Protest can highlight injustice, but it will require the best of the Black Lives Matter movement proposing new training, tools and tactics and yes, even joining the police department to personally implement those changes necessary for justice. It’s easy to condemn those who serve, but if working within the system is “selling out,” then justice is impossible.

Keep protesting. But when you don’t get the results you want, don’t just say “he’s not my mayor.” Run better candidates and campaigns. Make better arguments. Get more involved. If you fight and protest long enough, like Navy veteran Harvey Milk, you’ll eventually be asked to lead, to serve. It’s hard. Thankless. Dangerous. Do it anyway.

This op-ed was originally published in The San Francisco Chronicle.