Shortly after last month's Paris terror attacks, I wrote in this column of my newfound unease at commuting in New York. A month on, America has a new tragedy of its own and anxiety here is all the worse.
Since the San Bernardino attack, conversations about terrorism and the prospect of being killed in an attack have brought a macabre weight to American life I've not experienced before. For days after the attack, Americans obsessed over the motive: terrorism or a massacre? As if the answer meant something to the dead.
Barack Obama deemed it necessary to broadcast a reassuring message on Sunday night primetime, his first from the Oval Office since 2010.
Friends in New York have admitted they're as good as packing themselves. I've had a couple of nightmares.
Such is the extraordinarily disproportionate impact of terror.
If you consider the San Bernardino massacre - or any other Western terror attack - with cold dispassion, the whole thing makes for a sickly brilliant tactical concept.
After all, no one in America who took in the San Bernardino gore is comforted by the fact they probably have a greater chance of winning the lottery than of being caught in something similar.
As the drama of extreme and random violence is dissected and replayed and detailed in all its agony, is it really any surprise that a few minutes of gunfire totally spooked 350 million people?
If an unremarkable Christmas party for an unremarkable office in an unremarkable part of the United States could end in all that death, who is to say we might not all be next?
Logic is to say. But logic plays no part in dispersing fear.
Terrorists know it and it shapes their attacks. And Donald Trump knows it, which is why he bluntly attempts to turn a frazzled country's fear into votes.
Trump's suggestion to ban Muslims from entering the US is beyond cynical. It is as cruelly manipulative of his country's fears as the actions of the San Bernardino murderers.
• Jack Tame is on NewstalkZB Saturdays 9am-midday