Washington is in a state of stunned disbelief
Everything will go back to normal and everything has changed.
In New York, there is raw horror. In Washington DC, removed from the carnage over the river at the Pentagon, there is stunned disbelief.
Broadcasting last night from the top of a federal government building, everything seemed the same. Washington was quiet, no change there then, it is a quiet place.
The administrative centre of the city was deserted, but it always is at the end of the working day.
The streets were empty and it could have been a Sunday afternoon.
A golden sunset struck the Mall and the White House. The city seems a young and somehow unsullied place.
It looks very different from the Old World capitals like London, Paris and Madrid, with their constant reminders of past imperial glory and shame.
Invulnerability gone
One change brought about by Tuesday's attack is obvious, that sense of invulnerability, of being protected from territorial attack by two vast oceans, is now gone.
Analysts have warned of asymmetric wars for some time, the difficulty Goliath has protecting himself against David.
That abstruse language is now a reality for America.
The technological advantages that the US possesses seem useless.
There have been questions as to why planes were allowed into some of the most heavily restricted airspace in the world.
But no one yet suggested that either Manhattan or Washington DC be ringed with missile defences.
How do you guard against a rock thrown at a greenhouse?
Beyond the question of how this disaster could befall America, there will be the question of why. How any organisation or country could hate the US so much as to want to bring such death and destruction.
Hatred incomprehensible
Americans do not spend much time studying their own foreign policy. To many America is an ideal as much as a country - a shining city on a hill, dedicated to democracy and prosperity.
The idea that nations might dislike or hate America is an alien one. Often the words thrown against the country are met with a shrug.
That a country which has brought the good life to so many could be disliked with such ferocity is incomprehensible to many of its citizens.
That carefree ignorance is no longer tenable - that sense of invincibility, of prowess beyond one's years, an almost wilful ignorance, all the attributes of the young.
If and when the World Trade Center is rebuilt, the mourning finished, the terrible pictures and sounds relegated to the archive, that youthfulness of spirit may well remain the final casualty.