The United States of America has consistently relied on fear to create wars since WWII.
The fear of foreign combatants or invaders steels us til this day. Only problem is, this fear was only justified 2X in the last century (exempting imperialism).
Even a terrorist attack that takes out 3K people is a mere blip on the radar compared to the mass casualties of war the US has fought for 40 years.
Remember that the US is not lying specificallly. But the US is extremely cunning.