The attempt to detonate a car full of explosives in Times Square on Saturday may well have set off psychological tremors that will very quietly and very powerfully affect the citizens of New York City and the nation.

The fact that the explosives were not detonated has created a kind of emotional force field that has, thus far, kept our darkest thoughts at bay. What we say out loud is that we were lucky, and that is true. What we say out loud is that individuals, including Times Square street vendors, were astute and heroic. That is also true, as well as comforting.

We seem to be feeling . . . well, charmed. God or fate smiled upon us, and we very much seem to want to smile back.

We seem to be pleased enough to debate what to call the foiled plot. Was it an act of terrorism or was it not?

Relief is a potent drug, indeed.

Relief can, for a time, distract us from the stark fact that someone was able to drive a makeshift, very powerful bomb into the epicenter of Manhattan and come close to causing carnage that would have ripped open a massive wound in the psyche of our nation.

This was not, after all, the one-in-a-million shot of using box cutters to hijack jets and fly them into skyscrapers. This was not the destruction of a government building on our soil or an embassy on foreign ground. This was the near-death experience of one of our most well-known retail and entertainment centers. This was a close call and a stone’s throw from Toys "R" Us and the Marriott hotel. This is the kind of event that gets under the skin of average Americans who shop at malls and go to movie cinemas and stand in line for dinner at popular restaurants.

This near miss, while it may spark relief and denial for a few weeks, is likely to cause uneasy reflection in weeks and months to come. Because, ultimately, it shows we are not safe from mundane instruments of mass murder made of propane tanks, gasoline and alarm clocks, ignited by the unreasoned rage of our enemy.

Yes, our enemy. This is the sort of event that reminds us that we have one. We are at war with a network of terrorist nations and movements that sees our open and free society as malignant and worthy of destruction.

As our new reality—that of perpetual vulnerability—settles into our psyche, we would be wise to think about what is not being said right now that we ought to be speaking about. It’s time to talk to children in our schools about how they feel hearing that someone tried to blow up Times Square. It’s time to be wary of froth in the marketplace, keeping in mind that our recovery is fragile and can be blown apart by chaos and conflict. It’s time to think about how easy some people around the world may think it is to bleed this nation of its national character and natural courage.

As our border with Mexico hemorrhages and our enemies try to slice open major arteries in our urban centers, we have little time for relief. That dark reality of having to defend what we have built and come to love is, like it or not, making a comeback.

Dr. Keith Ablow is a psychiatry correspondent for Fox News Channel and a New York Times bestselling author. His book, "Living the Truth: Transform Your Life Through the Power of Insight and Honesty" has launched a new self-help movement including www.livingthetruth.com. Dr. Ablow can be reached at info@keithablow.com.

Dr. Keith Ablow is a psychiatrist and member of the Fox News Medical A-Team.