Has there been a more troubling time for free expression worldwide than right now?

I can’t remember one. Joel Simon, executive director of the Committee to Protect Journalists, has the numbers to back that up. The number of journalists, worldwide, in prison or killed while doing their jobs is at its highest since his organization began keeping records in 1992.

“This is the worst moment for journalists in recent history — and perhaps ever,” Simon told me this weekend. The most dangerous places are conflict zones, like Syria, and countries with repressive regimes, like Turkey.

When journalists are endangered, you can be sure that free expression is under siege.

The attempted coup in Turkey put a bright light on the perils: One Turkish photojournalist was killed. Other media people were forced, at gunpoint, to read a statement over the air.

And then there’s what’s happening in the United States, which sees itself as a stronghold of free expression.

As I write this, reporters are unpacking their flak jackets as they arrive by the thousands for the Republican National Convention in Cleveland.

With extreme racial and political tensions flaring, the convention could get ugly — for activists, for journalists and for law enforcement. (As The Washington Post’s Paul Farhi reported last week, attendees can carry guns into the conference zone, but police have banned gas masks, and even tennis balls.)

Frank Smyth, a former conflict reporter turned security expert, has trained hundreds of journalists recently. Cleveland police, he told me, are “using an iron fist” in not allowing gas masks. And he added: “If there was ever a time to ban weapons, this is it. It defies logic.”

In addition, the National Press Photographers Association is asking the Cleveland government to reconsider its prohibition of backpacks and large bags that photographers and TV journalists need to do their jobs.

Let’s hope the constitutional scorecard in Cleveland doesn’t read like this: Second Amendment: 1. First Amendment: 0.

Mickey Osterreicher, legal counsel for the NPPA, has trained police departments in Cleveland and Philadelphia. Both forces were receptive, he told me, to asking themselves the crucial question that will come up repeatedly: “Does the person have a legal right to be present?”

All of this is happening as Republicans prepare to nominate a candidate whose treatment of journalists, throughout his campaign, has been appalling. (As my colleagues Erik Wemple and Greg Sargent recently wrote, Hillary Clinton’s opacity, while a real problem, doesn’t compare.)

Simon sees strong connections between the problems in the United States and those worldwide.

“It’s all of a piece,” he said. “It’s the same challenges. They just aren’t playing out as dramatically here.”

Not yet, anyway.

Complicating matters everywhere is the huge technological disruption, as livestreams of sniper attacks, police shootings and attempted coups go viral. Every smartphone can be a live broadcast camera, and every eyewitness a citizen journalist.

That has obvious benefits for the flow of information. As Simon notes, one could get a sense of what was going on in Turkey, despite government attempts to shut down media outlets and platforms.

But the multiplicity of citizen journalists also means more people in danger, and prompts more efforts by autocrats to crack down.

What’s the answer?

Enlightened individuals, groups and governments need to speak out and to band together. Last week, 145 prominent tech-company executives signed a letter warning that Trump’s “vision stands against the open exchange of ideas, free movement of people, and productive engagement with the outside world.”

And PEN America, the free-expression organization, plans to deliver a petition Monday signed by 20,000 Americans including the authors Robert Caro, Martin Amis, Anne Tyler and Judy Blume, among many others. Joined by Reporters Without Borders and many other organizations, PEN is calling on both political parties to “create an open atmosphere for reporters” at the two conventions.

More pressure, in larger numbers, with more influential people involved, can make a difference. The same awareness, action and solidarity should happen on the global front, too.

The CPJ’s Simon wants to see “an international coalition that recognizes the importance of free expression.”

Back in 1970, another tumultuous time, Joni Mitchell sang a warning, “You don’t know what you’ve got till it’s gone.” In America and worldwide, we can’t let that happen to the free flow of ideas.