South Korea and Japan's feud explained
South Korea has terminated its military intelligence-sharing pact with Japan in the latest tit-for-tat dispute that has hit diplomatic and trade ties.
It comes after Japan removed South Korea's favoured trade partner status and imposed export controls on its important electronics sector.
The tensions go back over 100 years.
South Koreans want reparations for atrocities committed by Japan during its occupation of the Korean peninsula. But Japan considers the issue settled.
What has been affected?
Seoul said it had decided to end the intelligence-sharing pact because Tokyo's recent decision to downgrade South Korea's trade status caused a "grave" change in security co-operation between the two countries.
Japan's Foreign Minister Taro Kono called it a "complete misjudgement of the current regional security environment" and said Tokyo would "strongly protest" to Seoul about it. There has been no response yet from Washington, which had pushed for the pact three years ago, in part to help track North Korea's missile activity.
Earlier this month, Japan announced it would remove South Korea from its list of favoured trading partners - prompting a similar move from Seoul.
In July, Japan imposed export controls on materials used for memory chips and display screens - vital for South Korean companies like Samsung.
Stock markets slipped amid fears that the trade spat could badly affect electronics around the world.
The latest tensions stem from a South Korean court ruling last year that ordered Japanese companies to pay compensation to Koreans over forced wartime labour.
Mitsubishi Heavy, one of the firms involved, has reportedly refused to comply with the court order, while two other companies have had their assets seized in South Korea.
The issue has angered many in South Korea, with people boycotting Japanese goods. One man smashed up his Japanese-made car.
What's the history?
The two nations share a complicated history. They have fought on and off since at least the 7th Century, and Japan has repeatedly tried to invade the peninsula since then.
In 1910, it annexed Korea, turning the territory into a colony.
When World War Two began, tens of thousands of women - some say as many as 200,000 - from across Asia were sent to military brothels to service Japanese soldiers.
Many of these victims, known as "comfort women", were Korean. Millions of Korean men were also forcibly enlisted as wartime labourers.
Japan's rule of Korea ended in 1945 when it was defeated in the war.
In 1965, 20 years after Japan's defeat, South Korean President Park Chung-hee agreed to normalise relations with the country in exchange for hundreds of millions of dollars in loans and grants.
The issue of "comfort women" remains a sensitive one. Tokyo argues that the 1965 treaty that restored diplomatic ties and provided more than $800m in Japanese financial help, has settled the matter.
However, it remains far from resolved.
Why isn't the issue settled?
A deal was eventually signed in 2015. Japan apologised and promised to pay 1bn yen ($9.5m, £7.9m) - the amount South Korea asked for - to fund victims.
"Japan and South Korea are now entering a new era," Japanese Prime Minister Shinzo Abe told reporters at the time. "We should not drag this problem into the next generation."
But activists say they were not consulted, and rejected the deal. President Moon Jae-in, elected in 2017, suggested it be altered.
The historic dispute rumbles on, with neither country looking likely to bend.