In a magazine interview, Nishimura urged the Diet to consider arming Japan with nuclear weapons, despite the country's adherence to its post-war defense policy of three non-nuclear principles that ban the ownership, manufacturing or harboring of nuclear weapons. The only country to have had nuclear weapons used against it, Japan has been an adamantly anti-nuclear nation for more than half a century. On October 19, the Democratic, Social Democratic and Communist parties of Japan denounced the vice defense minister's remarks and accused Nishimura, a Liberal Party member, of making statements that ran counter to official Japanese nuclear policy. South Korea, which has cooperated with Tokyo on regional defense issues based on its non-nuclear policy, expressed "regret" over Nishimura's remarks and said it hoped his statements did not reflect official Japanese policy.China said it was "greatly shocked" by Nishimura's remarks, but was reassured by Tokyo's restatement of its official nuclear policy. Nishimura, who is known for his hawkish views and frequent public disagreement with Japanese policy toward China, first sparked controversy in 1997 when, in opposition to his government, he traveled to a South China Sea island claimed by both China and Japan, and planted a Japanese flag in an attempt to demonstrate ownership.