I agree. I'm no economist, but the modern economy seems brittle. Or to use another analogy, the motor runs very well until you throw a little sand in the gears--and the more efficient and delicate the motor, the quicker the crunch.
We rely very heavily on trust. I trust my neighbors not to shoot randomly around the neighborhood. If I lived on some streets in Milwaukee I couldn't rely on that, and I'd have to adjust my life accordingly: spending extra time checking the streets, making sure nothing is exposed outside, and (if I could afford it) fortifying the house. The time we spend on leisure or extra production when we can trust each other has to go to defense and backup when we can't. We'd plant no garden, nor care for the lawn, or do anything that would leave us exposed or distinctive.
A case in point is the sciences. We have come to rely on easy travel, so grad students and others can come to work in the US. With new restrictions (not always well implemented) after 9-11, the hassles have become great enough that anecdotal evidence suggests quite a few students have given up and are going to other countries instead.
You're right: we can lose this war in ways that don't involve a caliphate ruling us.