Guam is shaping up to be the focal point of the slowly intensifying crisis with North Korea. The major airfield on Guam, Andersen AFB is a hub for flying B-1B bombers to South Korea. Twice North Korea has threatened to strike Guam, most recently yesterday, because of the B1-B flights.

If this is true, the US may have responded four hours ago, treating the NK threat as a bluff. NK doesn't know yet. https://t.co/gbAWoWahtS — Adam Mount (@ajmount) August 11, 2017

"KONG 01" x2 ?? USAF B-1B Lancer bombers returning to Andersen AFB, Guam after another South Korea run. Working SFO on 17904 khz now ? pic.twitter.com/uilibvSr3m — Aircraft Spots (@aircraftspots) August 11, 2017

There it is. Per the Guam KCNA statements, this would be an important trigger condition for KJU signing the order for the Hwasong-12 launch. https://t.co/uugS9jXCrY — Ankit Panda (@nktpnd) August 11, 2017

And it seems like some North Korea missiles are in the process of being moved.

NEW: USG sources tell me Hwasong-14 (KN20 ICBM) and Hwasong-12 (KN17 IRBM) are now being moved. Unclear if possible launches imminent. — Ankit Panda (@nktpnd) August 11, 2017

("Now being moved" means in the past 12ish hours, I understand; could have been prior to the B-1B flight.) — Ankit Panda (@nktpnd) August 11, 2017

There are completely anodyne reasons for them to move missiles around the country that have nothing to do with imminent launch plans. — Ankit Panda (@nktpnd) August 11, 2017

This is still the first KN20 movement activity I've heard of since the July 28 launch. Longer still for the KN17. — Ankit Panda (@nktpnd) August 11, 2017

Japan has moved its Patriot missiles to attempt an interception, or so it seems, during the boost phase of any launch.

Japan to deploy Patriot missile defense batteries near North Korea’s declared missile course: report https://t.co/OKBcwgiOX6 — Alastair Gale (@AlastairGale) August 11, 2017

If North Korea does launch missiles towards Guam, the situation becomes extremely dangerous. A boost phase interception is not going to make the North Koreans happy. And US authorities will have a very short window of time, the time of flight is only 18-minutes, in which to decide if this is Kim making a statement or if the missiles contain nuclear warheads and this is a first strike.