Since our own horrific 9/11, AlQaida and the Islamic State have killed thousands of innocent people in terrorist attacks across the world.
But the carnage in Paris is different.
Not since World War II has Paris seemed so vulnerable - and if Paris is vulnerable so is the Western World.
Friday's attack was executed by eight suicide bombers who targeted locations crowded with people enjoying the start of the weekend.
The Islamic State is proudly taking credit for killing people sitting at outdoor cafés, attending a concert by an American band, and outside a crowded soccer stadium where even the president of France was present.
That the terrorists did not enter that stadium seems a blessing or the work of security personnel.
The Paris attacks will change America, too. Our presidential election just took a shot of sobering reality; our current president might now have yet another "American boots on the ground" decision to make.
Now, the tenor of the upcoming G20 summit in Turkey has a critical focus.
French President Francois Hollande said it simply: "It's an act of war." He's right and heaven help us all as to what that means for the U.S. and Europe.