Last week, President Barack Obama went to Europe to consult with allies about threats that lie beyond our borders. Back at home, we faced an even more sobering reality: It is not just our enemies from afar who have the potential to harm us. In the streets of our country, fellow Americans have been hurting one another.

Our split-screen culture often obligates us to hold two images at once, so this is what we saw: a president, traveling abroad, attempting to affirm America’s stature in the world, while in the states, citizens protested the death of two men in encounters with police, and a crazed gunman, in a sick revenge fantasy, killed five police officers in Dallas.

Protests elsewhere, including in Baton Rouge, grew tense, although luckily, at this point, no one else has died during protests. A worrisome weekend has reminded us of an abiding truth of this republic. No matter how large our Army or Air Force or Navy, America is only as strong as the bridges we build across our differences.

That is what we must remember in answering what happened last Tuesday, when Alton Sterling was shot to death outside a Baton Rouge convenience store during a struggle with police.

A federal probe of the shooting is underway, but the incident has prompted protests here and elsewhere, and those tensions grew deeper after another man, Philando Castile, was killed by police during a traffic stop in Minnesota. Both Sterling and Castile were black, raising concerns that their race figured into their deaths. A black sniper shot 12 officers and killed five during a Dallas protest on Thursday, telling authorities that he hated white people and was angry about what had happened to Sterling and Castile.

We had hoped these losses would link those on all sides in a mutual recognition that healing, not hurt, must be the order of the day. But the weekend protests in Baton Rouge showed how elusive that ideal remains.

Most protesters and police appeared to exercise restraint. But in attempting to block traffic on major arteries, some protesters threatened public safety. Isn’t there a better way to engage public sympathy in Baton Rouge than making the city’s already strained traffic worse?

And news that a police officer had his teeth knocked out by a flying object is also disturbing. No protester can hope to advance a moral cause by using an immoral end.

Meanwhile, video footage suggested instances in which police might have acted overzealously in arresting some protesters.

We’ve monitored the news these past few days as if tracking a tropical storm, tallying the injured and the dead, and wondering which roads are clear, what else might be broken. It has felt strange, and maybe there is some strength in remembering how strange it is. If we ever come to accept this anguish as normal, we will have defeated ourselves more decisively than any foreign enemy ever could.

Follow Kyle Whitfield on Twitter, @kyle_whitfield.​