When North Korea shot off its first-ever intercontinental ballistic missile in the early morning hours of July 4, U.S. military and intelligence personnel watched leader Kim Jong Un smoke cigarettes and stroll around the launchpad for a full 70 minutes, a source told The Diplomat's Ankit Panda.

The U.S. knew North Korea was in the final stages of building an ICBM after a recent rocket engine test. The U.S. knew North Korea liked to test missiles on Independence Day to send a message. The U.S. knew this missile was different than any they had seen before, and the U.S. knew it could destroy it with a variety of precision-fire platforms in the region. Importantly, the U.S. had Kim Jong Un in their crosshairs for over and hour, and they did nothing.

Those facts speak volumes about the security climate in the Koreas.

19 PHOTOS North Korea unveils new weapons at military parade See Gallery North Korea unveils new weapons at military parade North Korean leader Kim Jong Un applauds during a military parade marking the 105th birth anniversary of the country's founding father, Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj Missiles are driven past the stand with North Korean leader Kim Jong Un and other high ranking officials during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj TPX IMAGES OF THE DAY High ranking military officers cheer as North Korean leader Kim Jong Un arrives for a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj People react as they march past the stand with North Korean leader Kim Jong Un during a military parade marking the 105th birth anniversary of the country's founding father Kim Il Sung, in Pyongyang, April 15, 2017. REUTERS/Damir Sagolj TOPSHOT - Korean People's Army (KPA) tanks are displayed during a military parade marking the 105th anniversary of the birth of late North Korean leader Kim Il-Sung in Pyongyang on April 15, 2017. North Korean leader Kim Jong-Un on April 15 saluted as ranks of goose-stepping soldiers followed by tanks and other military hardware paraded in Pyongyang for a show of strength with tensions mounting over his nuclear ambitions. / AFP PHOTO / Ed JONES (Photo credit should read ED JONES/AFP/Getty Images) Korean People's Army (KPA) soldiers march on Kim Il-Sung squure during a military parade marking the 105th anniversary of the birth of late North Korean leader Kim Il-Sung in Pyongyang on April 15, 2017. North Korean leader Kim Jong-Un on April 15 saluted as ranks of goose-stepping soldiers followed by tanks and other military hardware paraded in Pyongyang for a show of strength with tensions mounting over his nuclear ambitions. / AFP PHOTO / Ed JONES (Photo credit should read ED JONES/AFP/Getty Images) North Korean leader Kim Jong Un waves to people attending a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj Military vehicles carry missiles with characters reading "Pukkuksong" during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj Members of the Korean People's Army (KPA) ride on mobile missile launchers during a military parade marking the 105th anniversary of the birth of late North Korean leader Kim Il-Sung in Pyongyang on April 15, 2017. North Korean leader Kim Jong-Un on April 15 saluted as ranks of goose-stepping soldiers followed by tanks and other military hardware paraded in Pyongyang for a show of strength with tensions mounting over his nuclear ambitions. / AFP PHOTO / Ed JONES (Photo credit should read ED JONES/AFP/Getty Images) North Korean soldiers march and shout slogans during a military parade marking the 105th birth anniversary of the country's founding father Kim Il Sung in Pyongyang, North Korea, April 15, 2017. REUTERS/Damir Sagolj An unidentified rocket is displayed during a military parade marking the 105th anniversary of the birth of late North Korean leader Kim Il-Sung in Pyongyang on April 15, 2017. North Korean leader Kim Jong-Un on April 15 saluted as ranks of goose-stepping soldiers followed by tanks and other military hardware paraded in Pyongyang for a show of strength with tensions mounting over his nuclear ambitions. / AFP PHOTO / Ed JONES (Photo credit should read ED JONES/AFP/Getty Images) People carry flags in front of statues of North Korea founder Kim Il Sung (L) and late leader Kim Jong Il during a military parade marking the 105th birth anniversary Kim Il Sung in Pyongyang, April 15, 2017. REUTERS/Damir Sagolj TPX IMAGES OF THE DAY North Korean soldiers march and shout slogans during a military parade marking the 105th birth anniversary of country's founding father, Kim Il Sung in Pyongyang, North Korea April 15, 2017. REUTERS/Damir Sagolj TPX IMAGES OF THE DAY A soldier salutes from atop an armoured vehicle as it drives past the stand with North Korean leader Kim Jong Un during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj North Korean soldiers march and shout slogans during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung in Pyongyang, North Korea, April 15, 2017. REUTERS/Damir Sagolj North Korean soldiers attend a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung in Pyongyang, North Korea, April 15, 2017. REUTERS/Damir Sagolj Attendees carry sheets in colours of the national flag of North Korea during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung, in Pyongyang April 15, 2017. REUTERS/Damir Sagolj North Korean soldiers, some of them on horses, march during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung in Pyongyang, North Korea, April 15, 2017. REUTERS/Damir Sagolj Civilian attendees watch North Korean soldiers marching during a military parade marking the 105th birth anniversary of country's founding father Kim Il Sung in Pyongyang, North Korea, April 15, 2017. REUTERS/Damir Sagolj Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

While it's "fairly standard that the U.S. didn't strike the missile ahead of the launch" Rodger Baker, the lead analyst of Asia Pacific and South Asia at Stratfor, a geopolitical consulting firm, told Business Insider, "the unusual aspect may be saying they were watching, or at least allowing that to leak."

Video of the launch clearly shows Kim on site, sometimes feet away from the missile. The next day, the U.S. and South Korea put on a blistering display of precision-guided firepower that proves they could have both killed Kim and stopped the launch in its tracks, but they chose not to.

By letting North Korea know they watched Kim out in the open as he prepared for one of his country's most provocative ever tests missile tests, Baker says the U.S. may have sent two powerful messages.

"They had a very easy shot at killing Kim and didn't," said Baker. This fits with Secretary of State Rex Tillerson's statement that the U.S. wants "to bring Kim Jong Un to his senses, not his knees," or that regime change is not the U.S.'s ultimate goal.

But regime security is the whole reason why North Korea wants long-range nuclear weapons in the first place.

If the U.S. demonstrates it's not intent on killing Kim, that could communicate that there's "no need to continue the [missile] program," according to Baker.

Secondly, "if the program is continued, we can strike it and Kim," said Baker. Though North Korea varies and tries to hide their launch points, the U.S. tracks them vigorously and footage of the launches always show Kim nearby.

Perhaps rather than kill Kim and trigger a North Korean response, which could be massive, the U.S. elected to signal to him that the best path to regime security would be to stay indoors and not play around near dangerous rocket engines, which have a habit of blowing up.

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