If solving the problem of school shootings were simple, we would have done it a long time ago.

It doesn’t matter whether you’re a Democrat or a Republican, liberal or conservative, urban or rural, a member of Everytown for Gun Safety or of the National Rifle Association. We are united in wanting to be sure that the kids we send to school in the morning come home safe in the afternoon.

But the slaughter of 17 people in the latest mass school shooting at Marjory Stoneman Douglas High School in Parkland, Fla., is a reminder that we can’t keep throwing up our hands, shrugging our shoulders, and offering thoughts and prayers. Nor can we keep rejecting possible responses because they won’t stop every killing in every situation.

It appears this massacre could have been prevented if the FBI had followed its own protocols after receiving at least two substantive tips that 19-year-old Nikolas Cruz was a time bomb set to explode in his former high school. That reality just reinforces the need for changes that will prevent one human error from leading to slaughter.

But we can’t immediately solve “America’s gun problem.” Mass shootings represent a small percentage of gun homicides, which cause far fewer deaths than gun suicides and accidents. And what happened in Parkland is different from mass shootings in workplaces, churches and open-air concerts.

Let’s try to address a specific need: providing the safest environment possible for U.S. schoolchildren.

We don’t need to vilify people or organizations for past action or inaction, nor should we promote proposals as “common sense,” implying that anyone opposed to them is insane. We need everyone at the table to make the case for why ideas would reduce the likelihood — not necessarily eliminate the possibility — of another Parkland.

A ban or extended waiting period on the sale of assault-style rifles or an increase in the purchase age to 21 must be considered, but not the seizure of weapons in private hands. Enhanced and more consistent background checks also should be explored.

Any laws involving guns must be enacted by Congress because one of the things we’ve learned from violence in Chicago and some other cities is that local gun controls don’t mean much in a nation built on easy interstate commerce.

Crucially, we cannot approach the problem only from the perspective of how to keep deadly weapons out of the hands of dangerous people. We must do more to secure our schools even when the Nikolas Cruzes of the world are armed.

Perhaps part of the answer is defensive firepower, whether that means more police or military veterans or other trained volunteers. But we have examples of effective defense in depth all around us in Jewish day schools and other private schools, which require visitors to be admitted through a perimeter fence and a secured door to get past a person inside. It’s not a foolproof system, but it makes an attack on students much more difficult.

We’ve talked a lot in this country about protective border walls and decaying infrastructure, but we must recognize that nothing is more urgent than ensuring that our schoolchildren are safe. We must make our public schools just as secure as our private schools.