There's a reason that U.S. ground forces haven't suffered a battlefield casualty from hostile aircraft since 1952, during the Korean War.

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At its inception in the late 1960s, Aegis was conceived as an integrated system of computers, radars and missiles for defeating hostile aircraft at sea.

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That edge is the main reason why no U.S. soldier has been killed by hostile aircraft since the Korean War, and no U.S. pilot has been downed by an enemy plane since the Vietnam War.

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And if soldiers still have to be sent, the Air Force has a good story to tell now about how it will support and protect them (no hostile aircraft has managed to kill a U.S. soldier since the Korean War due to American control of the skies).

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Aegis began as a sea-based defense against hostile aircraft, but over three decades has evolved to become the most versatile missile-defense system in the world, due in no small part to the fact that destroyers and cruisers hosting the system can get wherever they need to be quickly.

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An air marshal is an undercover armed guard on board a commercial aircraft to counter hijackings and other hostile acts.

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