(WN)The killing last week of Kim Jong-nam, the estranged half brother of North Korean leader Kim Jong-un, has fueled growing concerns about the country’s rogue regime. Here’s a look at what happened and the potential repercussions.  

***How did the killing happen?***

Two women are suspected to have killed Kim Jong-nam by wiping a poison-tinged cloth on his face as he was waiting to board a flight in Malaysia. Local authorities said the poison took effect quickly, and that he died on the way to a hospital.

Malaysian authorities have so far arrested four suspects in the case and are hunting for four North Koreans who fled the country on the day of the attack and three others. South Korea's acting president, Hwang Kyo-ahn, on Monday called the killing “an intolerable crime against humanity and terrorist act” masterminded by the North Korean regime.

Last Wednesday, South Korea’s spy agency said Kim Jong-un issued a "standing order" to murder his brother after he assumed power in late 2011. Lee Byung-ho, the agency’s chief, said North Korean agents tried to kill him at least once before succeeding last week, according to South Korean media reports.

***Why would Kim Jong-un want to kill his half brother?***

Mr. Lee said Kim Jong-nam hadn’t attempted to seek asylum in South Korea and that he was unaware of any attempts to depose his younger brother. Still, Kim Jong-nam was the only member of the North’s ruling family known to support political and economic reforms. He also publicly criticized the country’s dynastic approach to transferring power.

Kim Jong-nam was the eldest son and onetime heir apparent to late former North Korean leader Kim Jong-il. He was estranged from his family and had been living abroad for years. He reportedly fell out of favor with North Korea’s leadership when he was caught trying to enter Japan on a false passport in 2001, saying he wanted to visit Tokyo Disneyland.

An erratic leader, Kim Jong-un has purged more than 100 senior officials as he has pushed to consolidate his totalitarian power. In 2013, he ordered to execution of his uncle, once considered the country's second-most powerful man, for what the North alleged was treason. South Korean officials and North Korean defectors have called his deadly campaign a “reign of terror.”

***How does China fit into the picture?***

Beijing’s official reaction to the killing has been muted. Geng Shuang, a spokesman for the Foreign Ministry, said Friday at a regular news briefing that it would “keep following the developments of the incident.”

But behind the scenes Chinese leaders may have cause for concern. Some observers have speculated that the killing may have angered Beijing because Kim Jong-nam was considered a pro-Chinese candidate who could replace his younger brother should his regime collapse. He had been living in the Chinese-controlled territory of Macau for years.

Others say Chinese officials have long realized Kim Jong-nam lack of leadership potential and that his killing was no more than a cruel reminder of how unpredictable the North Korean regime is.

The killing comes at an uncomfortable time for Beijing. It occurred a day after North Korea test fired a medium-range ballistic missile, a provocation that led China to suspend all imports of coal from its troublesome neighbor. The North escalated its saber rattling last year by conducting two nuclear tests and testing 24 ballistic missiles.

“This year is crucial for North Korea nuclear issues,” says Wang Dong, director of the Center for Northeast Asian Strategic Studies at Peking University. He warns that the situation faces “sharp deterioration” and urges the United States and China to work closely in trying to stabilize it.

***How has the killing affected North Korea-Malaysia relations?***

The killing has raised tensions between the two countries. Malaysia's decision to carry out an autopsy and refusal to hand over the body directly to North Korea prompted Kang Chol, North Korea's ambassador, to accuse Malaysia of “trying to conceal something” and plotting to “besmirch” the North.

Malaysia has recalled its envoy from Pyongyang and summoned Mr. Kong to explain his remarks. The Malaysian government called them “baseless” and has told North Korea that it will give the body to Kim Jong-nam’s next of kin once the investigation is complete.

The fallout over the investigation puts North Korea at risk of becoming even more isolated globally. Malaysia is one a shrinking number of countries with which North Korea has diplomatic ties. It has 53 embassies and other foreign missions across the world, Reuters reports.