What significant geopolitical event involving Russia and Ukraine was reported on January 1, 2025?

Explanation

– On January 1, 2025, Ukraine formally stopped the transit of Russian natural gas through its pipeline network to Europe.
– This ended a decades-old transit arrangement, including the 2019 five-year deal between Kyiv and Moscow that had continued even after Russia’s 2022 invasion.
– The move cut off a major gas route to countries such as Slovakia, Austria, and Moldova, which had continued receiving Russian gas via Ukraine.
– Ukrainian officials framed the decision as denying Russia billions of dollars in wartime revenue.