[OldMissileer]

Blow the power grid, blow the water lines, blow any fuel supplies coming into the city. Blow rails, blow bridges.

Create a nearly impenetrable blockade then cut power and take out the sewage treatment plants. In less than a month they will be mostly dead from disease.

[DiogenesLamp]

Create a nearly impenetrable blockade then cut power and take out the sewage treatment plants. In less than a month they will be mostly dead from disease.

Modern cities are far more vulnerable than cities in 1860. It wouldn't take an army to bring a city to it's knees. Small bands of insurgents could knock out essential systems. American cities are simply not expected to deal with enemies at the gate.

It's virtually impossible to protect essential systems. We've relied too long on the idea that Oceans are our walls.