Here, counterproliferation capabilities such as improved passive defenses, as well as counterforce means such as deep underground attack weapons, play a central role in deterrence.

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And then there's the danger, as Hamm sees it, of federal regulation of fracking, which has come under attack for supposedly polluting underground water supplies.

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At the time, the Libyans claimed that it was so strong, so deep underground, it could withstand an aerial attack, a bombing attack.

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And during the Cold War, the U.S. government set up an underground bunker from which to operate in the event of a nuclear attack.

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If you enforce the law against people who hire people who are here illegally, whether they're doing it underground or above board, then that's the way you attack the issue.

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But he got America to spend billions upon billions of dollars on weapons, on underground shelters that he believed could save most people in a nuclear attack and on Star Wars.

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Dan Ingvaldson, a researcher at ISS, says movies, many of them not yet released to theaters, have made the rounds through these underground networks, making it conceivable that someone has already seen Star Wars: Attack of the Clones without having to pay for it.

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It is a U-shaped underground villa, built of metre-thick concrete slabs to withstand air and artillery attack.

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