Barring a change of heart, the US will likely have to resort to that proportional response it threatened against North Korea -- and details are emerging about that, too. Reportedly, the government is considering sanctions that would cut off North Korean leaders' access to cash, as well as internet attacks against their country's communications and military networks. The challenge is launching a digital assault that's damaging to the North's limited online infrastructure, but not so devastating that the nation retaliates in order to salvage its pride. As it is, the US may take its time developing any online attack strategy. Sabotage-oriented malware like Stuxnet (which many believe is a US creation) took years to develop, and even a relatively speedy campaign might take months.

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