The briefing took place in a war room where other maps of operational zones in South Korea and Japan were hanging on a wall right behind the North's leader. Beyond that, Papua New Guinea is 1,400 miles away, the Philippines are 1,600 miles from its shores, and Japan 1,623 miles.
Guam hosts two U.S. military installations and 6,000 USA soldiers - making it an attractive target for the North.
The U.S. military has a large presence here - its bases cover nearly a third of the island's land area - and prepares for worst-case scenarios like this.
The silver lining, in Burger's view, is that people in the mainland US now know more about his adopted home - an island that was a Spanish colony before the USA took control in 1898.
The Pacific Command, headquartered in Hawaii, determines if the missile poses a threat to Japan, South Korea, Guam or Hawaii.
But as Mr. Gardiner's scenarios have shown, the USA ability to quickly and decisively win a war is questionable - and North Korea's capacity to draw blood from any attacker makes it a more formidable adversary than numbers alone might suggest.
But he stressed the USA was pursuing "a very determined diplomatic effort" led by Secretary of State Rex Tillerson coupled with new financial sanctions to dissuade North Korean leader Kim Jong Un from further provocations.
The country's state-run Korean Central News Agency reported just hours later that the military "may send a strong message" it can take out military assets on Guam.
A Democratic congressman is urging House Speaker Paul Ryan to reconvene the House from its summer recess to consider legislation prohibiting a pre-emptive nuclear strike against North Korea.
There is a full interagency communication process during a North Korean missile launch which would involve command centers from the Pentagon, the intelligence community and major United States military commands overseas.
Two intelligence officials contacted by the paper confirmed the "broad conclusions" made by the shock report, which was dated July 28.
"It could escalate into war very quickly... yes, that's called war, if they shoot at us".
The last time North Korea fired missiles directly over Japan was in 1998, in a failed attempt to put a satellite, splashing down in the north Pacific.
"I'm working with Homeland Security, the rear admiral and the United States to ensure our safety, and I want to reassure the people of Guam that now there is no threat to our island or the Marianas".
As America's top military official arrived in South Korea, two of the Trump administration's most senior figures attempted to present a clear, united position on North Korea's ongoing threats.
If "the Yankees persist in their extremely unsafe reckless actions on the Korean Peninsula and in its vicinity", Kim continued, North Korea would "make an important decision as it already declared", he said.
"The circumstances are unfortunate but this is a good opportunity for us to educate the world about Guam and our culture, about where we are, and who we are", Guam Visitors Bureau marketing director Josh Tyquiengco told AFP.
"We have no desire to inflict harm on the long-suffering North Korean people, who are distinct from the hostile regime in Pyongyang".
President Donald Trump is warning of military action "should North Korea act unwisely".
The Sun revealed Britain would play no part in a military strike on the communist state in a move that was slammed as "weak and ill-judged" by ex-Commander of British Forces Afghanistan Colonel Richard Kemp. But officials in Guam, the tiny island territory that Kim Jong Un has threatened to attack, aren't keeping citizens in the dark.
"The people of our country are safe".
Responding to the tests, US President Donald Trump warned Pyongyang of "fire and fury like the world has never seen", while the North responded with the plan to fire missiles close to Guam.
"There are a lot of scenarios of tasks you might have to do during a very wide range of scenarios", he said.