Last year, the United States found itself inundated with headlines about nuclear capable intercontinental ballistic missiles. For the first time since the Cold War, Americans found themselves living with the specter of a nuclear attack, with North Korea’s Kim Jong Un testing a series of missiles and nuclear devices each aimed specifically at developing the capability to strike the United States.

For many, it served as the first time in their generation that a foreign nation offered so direct a threat to the American people. Sporadic terror attacks notwithstanding, the American public has been insulated from war via a powerful military apparatus and beneficial geography for decades — North Korea’s nuclear program may not be a particularly robust one, but it was a bullet with the American people’s name on it, and that tends to garner some attention.

Despite ongoing debate about how serious Kim may be about denuclearizing, the looming threat of nuclear attack has largely passed, allowing Americans to return to their normal lives… but within the Pentagon, defense officials have not enjoyed any such reprieve. While the North Korean nuclear threat may have waned, another arguably more pressing concern remains. Unlike the nuclear threat, we won’t be able to spot this one coming from space and no amount of firepower can intercept it. We won’t see it being fueled up in reconnaissance feeds. We won’t see massive test detonations in remote parts of the world.

The next weapon of mass destruction the Pentagon is worried about doesn’t have a trigger or a detonator, and nations could foreseeable develop it without the massive investments required of traditional WMDs. Cyber attacks, not nuclear weapons or biological agents, are now potentially the greatest threat facing the American people, and the Pentagon is looking for help developing ways to counter them.