Having issued an indirect travel alert "urging" US national to "depart immediately" from North Korea two weeks ago, the US State Department has escalated their perspective on US citizens' travel to, in, or through North Korea dramatically by declaring all U.S. passports invalid for travel, implicitly ordering all Americans out of North Korea from September 1st 2017.

ACTION: Notice of passport travel restriction. SUMMARY: The Department of State is declaring all U.S. passports invalid for travel to the Democratic People's Republic of Korea (North Korea) unless the travel meets certain criteria. DATES: The travel restriction is in effect on September 1, 2017. FOR FURTHER INFORMATION CONTACT: Anita Mody, Bureau of Consular Affairs, Passport Services, Office of Legal Affairs, 202-485-6500. SUPPLEMENTARY INFORMATION: The Department of State has determined that the serious risk to United States nationals of arrest and long-term detention represents imminent danger to the physical safety of United States nationals traveling to and within the Democratic People's Republic of Korea (DPRK), within the meaning of 22 CFR 51.63(a)(3). Therefore, pursuant to the authority of 22 U.S.C. 211a and Executive Order 11295 (31 FR 10603), and in accordance with 22 CFR 51.63(a)(3), all United States passports are declared invalid for travel to, in, or through the DPRK unless specially validated for such travel, as specified at 22 CFR 51.64. The restriction on travel to the DPRK shall be effective 30 days after publication of this Notice, and shall remain in effect for one year unless extended or sooner revoked by the Secretary of State.

The announcement comes as tensions continue to rise - and accelerate - over North Korea and its missile program, and just days after both North Korea and the US exchanged very symbolic ICBM test launches. Also, on Tuesday Senator Lindsey Graham said that President Donald Trump is considering war on North Korea if it continues its missile tests and nuclear weapons program.

And with US and China now trading barbs directly, with the smell of trade war in the air, Secretary of State Rex Tillerson said in a statement that

“China and Russia bear unique and special responsibility for this growing threat” posed by North Korea as they are the “principal economic enablers” of the country.

China’s President Xi Jinping responded, in his highly anticipated speech at the 90th-anniversary celebration of the founding of the People’s Liberation Army (PLA) on Tuesday, directing the military — which he heads — to be prepared for a military engagement at any time.

“Xi also asked the military to focus on preparations for war, and urged its leaders to improve capabilities in modern warfare and combat readiness. The military should be ready to win a war whenever needed, he said. “As commander-in-chief of China’s military, Xi said that with the unprecedented changes happening around the world, China’s armed forces are the bottom line guarantee for defending peace and security.”

Though he did not point to any situations specifically that would require China’s military to be at a default state of readiness for war, it’s difficult to imagine that Xi wasn’t referring chiefly to heightening tensions over North Korea.

Which leaves one question - what does the State Department know about September 1st? Here's one suggestion: with no US aircraft carriers currently off the Korean coast, as both departed in recent weeks

... it will take at least 2-3 weeks before they reassemble within striking distance of North Korea. September 1 should leave a comfortable cushion of time before the inevitable "next steps."