Park Geun-hye impeachment, THAAD rollout puts South Korea at centre of Asia's tensions
Beijing: A volley of rogue missiles, the surprise despatch of a military radar, and by week's end, the downfall of a president.
A confluence of events has stoked tensions on the Korean Peninsula, and analysts are worried about what happens next.
US begins THAAD deployment in South Korea
The US starts deploying the Terminal High Altitude Area Defense (THAAD) anti-missile system in South Korea in a move that is likely to deepen growing rifts with China.
The exit of disgraced South Korean president Park Geun-hye, after Friday's court ruling to uphold a decision by parliament to impeach her, leaves a vacuum at the centre of one of the globe's most dangerous flashpoints.
An increasingly reckless rogue nuclear state, North Korea, sits next door. As does an angry trading partner, China.
Anger in China as US missile defence system starts arriving in South Korea
The United States has relied on South Korea as a military ally, in punishing North Korean aggression through United Nations-enacted economic sanctions and US-led military exercises. Under new US president Donald Trump, North Korean policy was up for review with the potential to get tougher.
But can the US now rely on South Korea?
The United States move to deliver the first components of its Terminal High Altitude Area Defence (THAAD) to a base outside Seoul on Tuesday may well have been timed to start construction of the controversial system before Park's impending downfall.
Elections to choose her successor are due within 60 days, and the front runner in the polls is opposition Democratic Party leader Moon Jae-in, who has called for THAAD to be suspended and reviewed.
Trucks carrying parts of the Terminal High Altitude Area Defence defense system arrive at Osan air base in Pyeongtaek, South Korea. Photo: AP
Moon has also advocated a return to engagement with North Korea, an approach the US has rejected as rewarding bad behaviour.
The decision to accept THAAD has been polarising within South Korea. South Korea's relationship with China, which claims the US radar will be used to spy on Chinese missile tests, has soured. Unofficial economic sanctions have hit South Korean tourism operators, pop stars and retailers. Within China, protests calling for boycotts of South Korean products have mushroomed this week. Chinese foreign minister Wang Yi this week repeated calls for South Korea to "cease and desist" the THAAD deployment.
Park's fall is seen as favouring China, with a shift to the left in South Korean politics likely to be more receptive to Chinese pressure to abandon THAAD, and a different approach to North Korea's nuclear threat.
Wang warned starkly this week that China believed the US and North Korea were like two accelerating trains heading for collision.
China wants a return to the negotiating table, proposing North Korea suspend is missile testing in exchange for a halt to US and South Korean military exercises in the region.
Former US defence secretary William Perry said he believed diplomacy should be given another chance. Mr Perry, who led US talks with North Korea in 1999, told CNN he feared "the real danger is we will blunder into a war with North Korea".
Perry does not believe North Korea is preparing for a first strike. He said negotiations with North Korea could work if the US had limited objectives, and gave concessions.
US Secretary of State Rex Tillerson travels to South Korea and China next week to discuss the North Korean missile threat.
On Friday, as thousands of protesters massed on Seoul's streets and three were killed, China's foreign ministry said it hoped South Korea maintained political stability.
China's foreign ministry spokesman Geng Shuang said the THAAD deployment was "the crux" of the difficulties between the two countries.