2026年9月23日（水）コメンテーター：佐々木俊尚

Typhoon No. 25: Seven Dead in Chiba and Kanagawa, Defense Ministry Sends Disaster Relief

Typhoon No. 25 brought heavy rain that caused major damage across Chiba and Kanagawa prefectures. In Chiba, landslides killed five people and left two missing; in Kanagawa, two people died and three remain unaccounted for. The Ministry of Defense and the Self-Defense Forces accepted a disaster relief request from Chiba and have roughly 90 personnel deployed. Five rivers and marshes overflowed within Chiba, and in the Takasaki River basin in Sakura City, flooding submerged residential areas and temporarily isolated about 300 households. Sasaki Toshinao (佐々木俊尚) described how an acquaintance's neighborhood in Kamakura — the Onari-dori and Komachi-dori shopping streets — went underwater and turned into something resembling a river, and noted that mountainous areas like the Miura and Boso peninsulas are seeing damage unlike anything experienced before.

The Limits of Flood-Control Infrastructure and the SDF's Initial Response

Sasaki explained that Koshigaya Lake Town in Saitama escaped flooding thanks to its massive retention pond. Most Japanese cities design their drainage systems around roughly 50 millimeters of rain per hour, but this storm brought rainfall exceeding 100 millimeters. He pointed to emergency measures such as underground reservoirs in Shibuya and parking areas along the Tsurumi River near Shin-Yokohama that double as floodwater basins, as well as the Edo-period idea of the "kasumi-tei" — levees built with intentional gaps that let farmland flood in order to protect residential areas. He noted that the SDF had sent liaison officers to the affected areas even before the formal request to assess what support was needed, and suggested that AI and laser-surveying technology for terrain analysis will increasingly be used to predict landslide-risk locations going forward.

A Shift at Regional Banks and New Entrepreneurship Outside the Cities

Commenting on a front-page Nikkei story about major banks pursuing M&A for domestic investment, Sasaki said regional banks and credit unions are shifting away from a mindset of simply "securing surplus funds" toward actively seeking out investment opportunities. He observed that young people relocating to rural areas are starting new businesses, with shuttered shopping streets seeing old shopkeepers replaced and new stores opening in their place across the country.

The Paradox of Global Water Shortage and Japan's Excess Flooding

Sasaki pointed out a paradox: while the cooling needs of AI data centers consume enormous amounts of water and the Caspian Sea shrinks amid a global water shortage, Japan is instead struggling with too much water.

Ukraine's "Energy Ceasefire" and the Japan-US Summit in New York

President Zelensky said he was prepared to accept any format for a halt to attacks on energy facilities with Russia. Sasaki attributed the growing feasibility of such a ceasefire to Russia's national revenue being squeezed by strikes on its oil facilities, Ukraine's own depletion of air-defense missiles such as Patriots, and President Trump's interest in keeping gasoline prices down ahead of the November midterm elections — a ceasefire, he argued, that would benefit both sides. At the same time, the status of the Donbas region remains unresolved, and he noted a new phase of fighting involving unmanned surface vessels on both sides. In New York, Prime Minister Takaichi (高市) held her fourth in-person summit with President Trump, and according to accompanying reporters, the two held in-depth discussions on Indo-Pacific affairs and economic security ahead of the US-China summit scheduled two days later.