Residents and tourists in Hawaii were greeted with a terrifying message Saturday morning warning that they might have just moments to live as a missile was supposedly heading their way.
This message, as we now know, was a false alarm. But it does raise some serious concerns over U.S. defense and emergency management capabilities at a time when the potential for such a disaster is as high as it has been since the Cold War. What if it wasn't a false alarm? What if there was, in fact, a North Korean missile headed towards Hawaii?
The Hawaiian government is more than aware that it is under threat, and until recently, it appeared to be doing a pretty decent job preparing for the highly unlikely, but potentially devastating, worst case scenario. Under current Gov. David Ige, the state has been testing air raid sirens across the state on a monthly basis since December, published a guide on what to do in the event of a nuclear detonation last summer, and has engaged in town halls to help inform the public about the nuclear threat. It even has a free app that residents can download to receive up to date information on disaster scenarios.
Hawaiian politicians in Congress have also taken the lead in response to the false alarm to make sure their state is prepared.
"I'd like to work with you to ensure we're providing specific instructions on what to do upon an alert," Homeland Security Secretary Kirstjen Nielsen told the Sen. Mazie Hirono (D-HI) during a Senate Judiciary Committee on Tuesday. "We provide the backbone to ensure that at any time, if the president or the Department of Homeland Security would need to send an alert to citizens with an impending catastrophic event, for example, we can do that."
But if Hawaii was somehow struck by a nuclear weapon, officials are under no illusion that it would be a devastating event. When a Hawaiian legislator suggested the idea of creating a nuclear shelter out of old military bunkers, Hawaii Emergency Management Agency administrator Vern Miyagi put the idea to bed.
"There's no such thing as a blast shelter," Miyagi told Stars and Stripes in July. "If you're at ground zero, you're not going to survive."
North Korea tested a nuclear warhead in 2013 with a yield of up to 10 kilotons, approximately half the size of the bomb the U.S. dropped on Nagasaki, Japan. While comparatively smaller, if North Korea was able to mount a warhead of similar yield on a missile, it could take out a huge portion on downtown Honolulu, according to NukeMap.
North Korea also tested what it claimed was a hydrogen bomb in 2016. With an estimated yield of up to 100 kilotons, it was ten times larger than the 2013 test. If North Korea was able to mount a weapon of similar size, it could effectively destroy the city entirely.
In either case, Hawaii's Emergency Management Agency estimates residents would have only 20 minutes to seek shelter.
Of course, North Korea's nuclear team would first have to figure out how to miniaturize a nuclear warhead to make it small enough to put on a missile, a feat they apparently have yet to master. Then they would have to make sure their inter-continental ballistic missiles were reliably accurate enough to hit Hawaii. At least one of North Korea's missiles has the range to hit most of the U.S., but it's unknown if they are accurate enough to hit an island chain in the middle of the massive Pacific.
The U.S. has a few options if North Korea ever was able to launch a missile, but like any system, they have their limits. The Terminal High Altitude Area Defense (THAAD) is one of the more notable systems that has been in the headlines recently. But it might not be able to defend Hawaii.
"As for our defense capabilities, THAAD is a extremely capable system," said John Capello, a former Air Force officer who served as an analyst for the U.S. Missile Defense Agency and current senior fellow at the Foundation for Defense of Democracies, told me in an email. "But as you know it has to be deployed in a position relative to the target area for it to defend that area. So the system deployed in Korea or Japan cannot defend Hawaii."
There's also the Ground Based Interceptor (GBI), a weapon tailor made to knock out ICBMs as they sail through the sky. But according to Cappello, the GBIs based in California would be unable to defend Hawaii.
Finally, there is the Aegis missile cruiser, a ship packed with anti-missile weapons. Cappello was uncertain if any were currently based in Hawaii, but there was talk of converting a ground-based Aegis test site in Hawaii into a fully operational site in 2016.
There is even a theory that an F-35 could be used to help shoot down a North Korean missile using its highly advanced sensor suite to help track it as it leaves the launch pad, giving U.S. interceptor systems a better chance. It's interesting, but little more than theoretical at this point.
Any successful nuclear attack from North Korea would require a lot to go right for the North Koreans and a lot to go wrong for the U.S., but Hawaii is preparing nonetheless. Even if it messed up this time.