Speaking at yesterday's memorial service for the 12 people murdered at the Washington Navy Yard last week, President Obama dared Americans to "care enough" to do something about gun violence. Exactly what we are supposed to do was far from clear, however:

These families have endured a shattering tragedy. It ought to be a shock to us all as a nation and as a people. It ought to obsess us. It ought to lead to some sort of transformation. That's what happened in other countries when they experienced similar tragedies. In the United Kingdom, in Australia, when just a single mass shooting occurred in those countries, they understood that there was nothing ordinary about this kind of carnage. They endured great heartbreak, but they also mobilized and they changed, and mass shootings became a great rarity.

And yet, here in the United States, after the round-of-clock coverage on cable news, after the heartbreaking interviews with families, after all the speeches and all the punditry and all the commentary, nothing happens. Alongside the anguish of these American families, alongside the accumulated outrage so many of us feel, sometimes I fear there's a creeping resignation that these tragedies are just somehow the way it is, that this is somehow the new normal.

We can't accept this. As Americans bound in grief and love, we must insist here today there is nothing normal about innocent men and women being gunned down where they work. There is nothing normal about our children being gunned down in their classrooms. There is nothing normal about children dying in our streets from stray bullets.

No other advanced nation endures this kind of violence—none. Here in America, the murder rate is three times what it is in other developed nations. The murder rate with guns is ten times what it is in other developed nations. And there is nothing inevitable about it. It comes about because of decisions we make or fail to make. And it falls upon us to make it different….

I've said before, we cannot stop every act of senseless violence. We cannot know every evil that lurks in troubled minds. But if we can prevent even one tragedy like this, save even one life, spare other families what these families are going through, surely we've got an obligation to try….

We Americans are not an inherently more violent people than folks in other countries. We're not inherently more prone to mental health problems. The main difference that sets our nation apart, what makes us so susceptible to so many mass shootings, is that we don't do enough—we don't take the basic, common-sense actions to keep guns out of the hands of criminals and dangerous people. What's different in America is it's easy to get your hands on gun—and a lot of us know this. But the politics are difficult, as we saw again this spring. And that's sometimes where the resignation comes from—the sense that our politics are frozen and that nothing will change.

Well, I cannot accept that. I do not accept that we cannot find a common-sense way to preserve our traditions, including our basic Second Amendment freedoms and the rights of law-abiding gun owners, while at the same time reducing the gun violence that unleashes so much mayhem on a regular basis. And it may not happen tomorrow and it may not happen next week, it may not happen next month—but it will happen. Because it's the change that we need, and it's a change overwhelmingly supported by the majority of Americans.

By now, though, it should be clear that the change we need will not come from Washington, even when tragedy strikes Washington. Change will come the only way it ever has come, and that's from the American people. So the question now is not whether, as Americans, we care in moments of tragedy. Clearly, we care. Our hearts are broken—again. And we care so deeply about these families. But the question is, do we care enough?

Do we care enough to keep standing up for the country that we know is possible, even if it's hard, and even if it's politically uncomfortable? Do we care enough to sustain the passion and the pressure to make our communities safer and our country safer? Do we care enough to do everything we can to spare other families the pain that is felt here today?

Our tears are not enough. Our words and our prayers are not enough. If we really want to honor these 12 men and women, if we really want to be a country where we can go to work, and go to school, and walk our streets free from senseless violence, without so many lives being stolen by a bullet from a gun, then we're going to have to change.