The four were in China for a project commissioned by the Japanese government to dispose of chemical weapons abandoned by the Japanese military after World War II. Chinese officials also suggested the possibility of banning exports to Japan of rare-earth elements – raw materials crucial for many Japanese manufacturing processes – and appear to have done so informally.
更过分的是，中国以涉嫌间谍活动的理由逮捕了日本藤田公司的四名日本雇员。但这四人实际上是受日本政府委派，来华处理二战日军遗弃化学武器的。中国官员还声称可能停止对日稀土出口——这是许多日本企业生产所必须的关键原材料——也最终实施了非正式的稀土禁运。