Regarding the April 17 front-page article “The day after, combing for clues”:

I’ve been struck by how many conversations I’ve heard, both public and private, that focus on the suddenly imaginable possibility that we’ve entered a period in history when Americans face threats from bombings aimed at civilians. Experts have predicted this possibility for years. So have novelists and screenwriters.

If it happens, it will be a different sort of mayhem than the kinds we have faced in the past. It will require no more of us than has already been demonstrated by people who work at dangerous jobs, or by victims of abuse and battering, or by children who grow up in dangerous places.

Each death from terrorism will be a tragedy. But it will also be a profile in courage of those who choose to continue living in public places. The individual suffering may be horrific, but collectively we will survive it and, even, transcend it. A test of shared courage, perhaps, but exactly what we ought to expect of ourselves.

Jeff Epton, Washington

I was deeply perturbed to read the April 17 news article “Worry about attacks has faded since 9/11,” discussing how Americans feel safer and have become less vigilant to suspicious activity. In light of the Boston Marathon bombing, it is clear the United States still faces threats domestically and abroad. Americans need to remain aware of their surroundings, and additional precautions need to be implemented. The decision by the Transportation Security Administration in March to allow small knives on airplanes only adds to the risk of attacks.

The United States needs to heighten security, not lower it. The Boston Marathon and Newtown, Conn., attacks are reminders of the type of terrorism acts that can happen at home. We can never forget. Once we do, we will be at even greater risk.  

Catherine Weckenman, Washington

When bombs exploded at the finish line of the Boston Marathon, it took only seconds for emergency responders and ordinary citizens to rush toward the wounded. Police helped transport the injured, while civilians applied pressure to the open wounds of strangers. And runners at the end of 26.2 miles of intense exertion ran on to donate blood at local hospitals, while homeowners along the marathon route opened their doors to unfamiliar faces.

In 16 seconds, two bombs rattled the world. But in the minutes and hours that followed, Bostonians made it perfectly clear that the attack on the marathon had failed.

While lately it seems that our country has been stretched to its breaking point by senseless, everyday violence, Monday’s attack proved that, no matter the scale or severity of violence and no matter the motive or message, Americans will not flee in fear. We stand firm in the face of terror. We disregard our personal security to help the wounded. And we never fail to honor the fallen by rising from the ashes.

Mike Kandel, Washington

Regarding the April 17 news article “Defining ‘terror’ can be a struggle”:

As an independent conservative who grew up in and around the Dorchester area of Boston, where the youngest victim of this terrorist attack — 8-year-old Martin Richard — lived with his family, I was quite saddened by the instant, and totally inappropriate, charges leveled against President Obama by some on the right because he did not utter the word “terrorism” in his first public remarks on the Boston Marathon bombings. Give the president a break and give the victims the honor and the dignity they deserve. At what point do we leave partisanship, bias and even hate out of our disputes, out of respect for those who are suffering?

Do some on the right who would attack Mr. Obama at such a time truly believe that he does not want to keep the country, which is the home to his children, safe? Do these critics truly believe that, as a father of two, he does not grieve for little Martin or for all those who now will go through the pain of loss?

Yes, this was an act of terrorism. The answers on who and why are to follow. Regardless, Boston and our nation were attacked, and Barack Obama is our president and the commander in chief of our armed forces. Respect his high office and give him a chance to do his job.

Douglas MacKinnon, Boca Raton, Fla.

Douglas MacKinnon served as a writer on the White House staffs of presidents Ronald Reagan and George H.W. Bush.