North Korea has, since its third test of a nuclear bomb in mid February, been issuing escalating threats against the US and South Korea.
Explicit warnings that it will launch rockets, missiles, even a pre-emotive nuclear strike.
Yesterday the US Air Force flew two of its B-2 Stealth Bombers, which can carry nuclear bombs, on training missions over South Korea.
The aircraft carried out a dummy bombing raid over a firing range.
The US Embassy in the South Korean capital tweeted pictures (no photo shop required) of the distinctive bomber refuelling and made the point that the aircraft can hit targets "at will".
Clearly the US was sending a clear signal reminding the North Korean leadership that it cannot stop the might of the US military.
The reality is that North Korea is not believed to have the sophisticated missiles which could successfully hit US targets in Guam, Hawaii or mainland USA, as they have threatened to.
The recent rocket launches, in April and December 2012 used technology that NASA was using in the 1960s, according to space experts.
Like the photo shopped pictures which doubled the number of military hovercrafts storming a beach during exercises, North Korea's military capabilities are often exaggerated.
However, it's foolish to ignore threats.
Using a torpedo and artillery the North Koreans launched two attacks in 2010 which killed a total of 50 South Korean sailors and civilians.
The location of the South Korean capital close to the border with the North means millions of people are within artillery range.
Kim Jung Un doesn't need a missile to hit Seoul.
How seriously are these threats being taken? Two things suggest we are not on the brink of a nuclear war on the Korean peninsular.
The Kaosong joint industrial park run by North and South is operating as normal, plus the US State Department has not given an order for US citizens to leave South Korea, which it would have to issue if there was a real threat of imminent armed conflict.
The question is; now that Kim Jung Un has issued blood chilling war cries for weeks, can his authority be damaged if he doesn't go through with his threats?
Not if he gets something in return; and that may well be a revival of talks which could lead to aid.
That would enable Kim to present himself as the winner: who forced his enemies to the negotiation table.
North Korea and its leader Kim Jung Un knows very well that current US and South Korea military planning suggests a war would be over very quickly.
Launching a missile would be futile and suicidal.
According to James Hardy, Asia-Pacific Editor for IHS Jane's Defence Weekly, the US "provides its nuclear umbrella to South Korea (and its other East Asian allies) through the Ohio class submarine fleet, of which eight area are assigned to the Pacific. They make regular port calls in South Korea."
In other words, if the North launched a weapon of mass destruction, Pyongyang could be flattened in minutes.
I also asked James how quickly the US and South Korean forces would pick up the launch of a missile and he replied "NORAD (North American Aerospace Defence Command) has a pretty quick turnaround on spotting missile launches – it tracked the previous rocket launches in real time, and one would assume that Aegis equipped ships and the early warning radars in Japan and Taiwan would be tasked to track and deal with any long-range missiles. In terms of shorter range threat, that would likely fall to the Patriot batteries on South Korean territory."
No wonder China calls Kim Jung Un's threat to use nuclear weapons "reckless".
The US, South Korea and Japan now have every opportunity to continue to build up military forces and anti-missile defences right on China's doorstep.
The threat to Kim Jung Un is lasting damage to his relationship with Beijing, his one powerful ally, and the only reason his regime remains in power.