The theme for the opening night of the 2016 Republican National Convention, "Make America Safe Again," has certainly taken on additional emotional resonance in the wake of tragic police shootings in Dallas and then again in Baton Rouge over the weekend. Fortunately, however, the assumption that underlies the theme -- America is not safe, the long-term trends are going in the wrong direction, everything is going to hell in a handbasket -- is demonstrably false.

We are safer than we have been in decades.

Take a look at what has happened to violent crime in the decade between 2005 and 2014, the most recent year for which we have full national data:

Over that decade, the overall rate of violent crime has fallen by 22 percent; the violent crime rate in 2014 was the lowest in the previous 45 years. The murder rate is down by 15 percent, and was the lowest since at least 1960; rape and robbery are down significantly as well. And while some in media and politics would like to portray the problem as intractable, focusing on the isolated example of Chicago, the number of homicides within the black community has been declining at a faster rate than the number of homicides overall.

It's also worth noting that these trends have continued through the Great Recession, even though economic hard times are often associated with rising crime. In addition, the rate at which we incarcerate people in this country peaked back in 2008, and since then both the incarceration rate and the crime rate have continued to fall.

Now, the numbers above don't make very good headlines, and the story they tell is understandably overwhelmed by the public's natural horror at the mass assaults conducted by the likes of Omar Mateen in Orlando, Dylann Roof in Charleston and Adam Lanza at Sandy Hook Elementary. Those numbers tell us that we are not a nation in decline, unable to live in peace and security with each other. If we compare it to the historical data, they tell us that even with occasional spasms of violence, America in 2016 is safer than it has been in about half a century. We have been getting better, not worse.

But history also tells us – it tells us loudly and insistently -- to beware those who seek power by telling you to be very very afraid, and who then conveniently offer themselves as the antidote to that fear.