For example, China could make its continued support for sanctions conditional upon reaching a deal with the US over the geopolitical orientations of a future united Korea, says Katsoras. But if North Korea succeeds in building nuclear missiles that can reach the continental US, the equation changes.
Those fears spiked when it became clear that the trajectory of the four missiles that Kim meant to fire at the Pacific island of Guam would take them over southern Japan.
The war games, which last 11 days, involve 17,500 US service members, including about 3,000 from outside the peninsula, and 50,000 South Korean troops.
South Korean President Moon Jae-in said on Thursday U.S. President Donald Trump has promised to seek Seoul's approval before pursuing any option against nuclear-armed North Korea.
Joseph Dunford, the chairman of the Joint Chiefs of Staff, said in Tokyo on Friday that an attack on Japan or the U.S.is "an attack on both of us". The exercise involves 17,500 American troops and 50,000 South Korean soldiers, according to the US military command in South Korea and Seoul's Defense Ministry. More North Korean bombs could indicate second-strike capacity and then there are questions about how much nuclear firepower the country could mobilize on a moment's notice.
Turnbull said Australia called on all countries to "redouble their efforts, including through implementation of agreed United Nations security council resolutions, to bring North Korea to its senses and end its reckless and risky threats to the peace of our region and the world".
A second US official added that North Korea has had parts in place for a nuclear launch for months, but no new activity had been seen recently.
This EPA photo shows, from R to L, U.S. Defense Secretary Jim Mattis, Secretary of State Rex Tillerson, Japanese Foreign Minister Taro Kono and Defense Minister Itsunori Onodera at "2+2" talks at the Department of State in Washington on August 17, 2017. "They can not cast off the yoke of dependence on foreign powers, and are pulled along by the chain of subordination to the United States". U.S. officials say the exercise is created to "increase readiness", though again this comes after weeks of claiming that USA troops were already ready for war with North Korea at a moment's notice.
If North Korea uses the drills this week as a reason to launch missiles around Guam or elsewhere, it could set off a new cycle of escalation. While North Korea later said it was holding off firing towards Guam, tension remains high and annual joint military exercises by the United States and South Korea beginning on Monday are likely to enrage Pyongyang.
"The bottom line is that we really don't know how many nuclear weapons they have", said Bruce Bennett, a senior worldwide and defense researcher at RAND specializing in northeast Asian military issues.
It sparked an intense war of words between the two sides that included a direct threat against the US' overseas territory of Guam - which is home to an American military base. "I believe China has strongly warned North Korea not to conduct another nuclear test", Moon said.