North Korea experts have revealed a military strike would kill tens of thousands in the first few hours, and Australia would also be impacted.
The rogue state reportedly has the ability to launch 4000 rounds of artillery an hour, killing up to 64,000 people in a day – most of those within hours of three hours, according to a 2012 Nautilus Institute report.
In South Korea, the city of Busan would be in range of nuclear and ballistic missiles, overpowered by the American THAAD anti ballistic missile defense system might.
The Super Shield would defend against some of the strikes, but not all, the Sydney Morning Herald reports.
Should the Kim Jong-un regime’s threats to turn the South into “a sea of fire” be realised, its capital Seoul would be largely unprotected against fire from the demilitarised zone, according to reports.
There are about 100,000 Americans living in the South's capital, with a population of 25 million, and experts predict US military bases would be targeted there, as well as in Japan.
US allies, including Australia, could also consider a limited punitive strike against the South as message to stop its nuclear program, according to reports.
The probable strikes have been likened to those launched on Donald Trump’s call to target the Syrian regime after its alleged use of chemical weapons.
However, experts argued if the US President lost patience with the Kim regime’s resistance and decided to launch a pre-emptive strike against its nuclear program, those could result in a wide scale assault, with North Korea's military being the fourth-largest in the world.
Trump would need to weigh up if the strikes were worth the lives of hundreds, or possibly thousands of Americans, in addition to tens of thousands of South Koreans.
“If this goes to a military solution, it's going to be tragic on an unbelievable scale,” US Defence Secretary James Mattis said.
Australia would most certainly be involved if the North launch an attack on the South, under the 1953 armistice.
The Japan-based United Nations force to support South Korea is currently commanded by an RAAF officer, according to the Sydney Morning Herald.
A spokesman for Defence Minister Marise Payne told the newspaper she would not comment on "hypotheticals about what Australia might do in the event of a contingency on the Korean Peninsula", but said the Armistice agreement was "not a mutual defence agreement".
Australian Strategic Policy Institute head Peter Jennings said the nation was obliged to join the fight “whether we like it or not” because our US alliance and close economic relationship with South Korea.