Leah reflects on one incident that triggered her fears, when her investors threatened to shut her down. "I was probably up against the most fear I've ever had." she says.

Is there a danger that America will choose, in the end, to retreat behind a different kind of shield-not one that guards against missiles, but one that aims to shut out the world?

And proceeds to do the only thing he can do to defend himself against Hal, which is shut down the program, basically killing — if we can talk that way — killing Hal.