On 9/11/2001, the United States discovered what it means to be the target of international terrorism.
New York and New Yorkers were shaken in a way that most of us living away from that city cannot easily comprehend. After the initial shock of death and destruction, there was a hole in the skyline, a daily reminder of the loss of colleagues, family and friends.
On the 10th anniversary weekend of 9/11, Homeland Security officials announced a "credible threat" of a new terrorist attack on New York.
Police and National Guard armed with automatic weapons were suddenly everywhere, checking out box trucks, guarding tunnels and bridges, and keeping an eye out for suspicious vehicles and people. It was not the time to tell a joke.
How have New Yorkers responded? The U.S. Open fought with the weather over the weekend, but crowned new tennis champions, even if a day late.
New York goes on undeterred.
This is Fashion Week in New York, with new, trendy clothing being tried on and tried out all over Manhattan.
Leaders from around the world are also in town for a United Nations conference. The predictable traffic jams guarantee that cab drivers will provide near-death experiences for their fares.
In other words, New York is as vital as ever. Terrorists forced more vigilance, but they failed to paralyze the city with fear. Osama bin Laden and his lieutenants are dead or in hiding while New York and New Yorkers, despite the hole that will never be filled, show us all how courage and hope beat fear and despair every time.