Donald Trump may come to rue his brazen "fire and fury" military threat against North Korea, which has escalated the risk of a nuclear war in north Asia to an unprecedentedly dangerous level.
Unless the US President is truly willing to pre-emptively strike Pyongyang – a frightening proposition – the warning could match president Barack Obama's hollow and credibility-sapping "red line" threat against Syria.
John McCain, the Republican chairman of the Senate Armed Services Committee on Wednesday observed: "The great leaders I've seen don't threaten unless they're ready to act, and I'm not sure President Trump is ready to act."
"I take exception to the President's comments because you got to be sure you can do what you say you're going to do."
Trump's ramped-up ultimatum, in effect, dared North Korean dictator Kim Jong-un to test the US President's threshold for conflict.
"North Korea best not make any more threats to the United States," Trump said while vacationing at his golf club in New Jersey.
"They will be met with fire and fury like the world has never seen."
His rhetoric implies that another verbal threat by Kim could trigger a US military response, though there was some ambiguity in what Trump meant by "threats".
Did he mean merely another vocal threat or a more serious physical targeted missile launch by North Korea?
Within hours North Korea's state media tried to call Trump's possible bluff. It claimed the North Korean military is "examining the operational plan" to strike areas around the US-military airbase on the US Pacific island territory of Guam with medium-to-long-range ballistic missiles.
US officials believe North Korea has the capability to strike the US and some intelligence officers reportedly think it has has successfully produced a miniaturized nuclear warhead that can fit inside missiles.
Trump has left himself exposed to look either weak through inaction or he will be forced to back up his warning by launching a dire pre-emptive US strike.
US president Theodore Roosevelt once famously said, "speak softly, and carry a big stick."
Defence experts are unanimous that nuclear war on the Korean peninsula would kills hundreds of thousands, or even millions of people.
Neighbouring Seoul is a high-density city with 10 million residents. Japan is also within range of Pyongyang's dozens of short and medium range missiles.
China's potential response to a US strike would be highly uncertain, given its border with North Korea, historic communist ties and staunch opposition to a unified Korea.
Even some of the most hawkish national security professionals in Washington are adamant that a pre-emptive strike is not a viable US option, unless Kim is poised to launch an intercontinental ballistic missile at the US or its allies.
US Defence Secretary James Mattis warned in May that conflict in North Korea would be "catastrophic" if diplomatic efforts failed.
Until now, Trump had been clever to leave all options on the table and decline to telegraph potential US responses.
His reckless statement has painted himself into a corner and raises the stakes considerably.
It was a sharp deviation from the successful US-sponsored United Nations resolution last week imposing tougher sanctions against North Korea and Secretary of State Rex Tillerson's failed efforts to lower the temperature with Pyongyang.
It is unclear if Trump's rash warning was pre-planned or he simply broke into it spontaneously while being pressed by reporters during a briefing about his crackdown on the opium drug epidemic crippling the US.
Perhaps he is trying to exert even more pressure on China to rein in its estranged ally North Korea - a necessary tactic.
One of Obama's biggest foreign policy blunders was to issue his chemical weapons "red line" threat in 2013 to Syria's Bashar al-Assad, only to fail to follow through when the vicious dictator launched the weapons on his own people.
The backdown made the US under Obama look feeble and emboldened rivals such as Russia in eastern Ukraine and China in the South China Sea to aggressively expand their territorial control.
Trump, the master of bluster, may have fallen into the same trap.
Though Trump is signalling the unthinkable may be possible. That is, if he is prepared to cross his red line rhetoric and wage a devastating war.
