Communist Party upper house member Yamazoe Taku criticized Defense Minister Koizumi Shinjiro on November 2, 2026, over his reaction to a US AI system the Defense Ministry plans to bring into Self-Defense Forces command and control. In a post on X, Yamazoe questioned the system's safety and who bears legal responsibility for it, then turned to Koizumi's praise of it: "How utterly repulsive that Minister Koizumi innocently extols it as 'really good.'"
Yamazoe was responding to reporting that the ministry will fund the AI introduction in next fiscal year's budget. The system was developed by Palantir Technologies with the US military, and Yamazoe wrote that it is suspected of having brought about a war crime through a "mistaken bombing" of an elementary school in an attack on Iran. "The Japanese government is avoiding a legal assessment of it," he wrote.
A demo in Washington
Koizumi visited Palantir's office in Washington in January 2026, according to the Mainichi Shimbun. There he watched a demonstration video of Maven Smart System, the AI command-and-control platform the company provides to the US military, and was heard to say, "Really good."
The visit was scheduled to coincide with talks with the US defense secretary and reflected Koizumi's wish to learn about "new ways of fighting," the Mainichi reported.
The exchange leaves open the question the plan raises: a foreign vendor's software sits inside the chain that decides how Japanese forces fight, while Tokyo has not said publicly how it judges the system's record or where liability would fall if it failed.