The Wall Street Journal reports:

Ukrainian forces seized most of a strategically vital city in northeastern Ukraine on Saturday, cutting the main supply line to thousands of Russian troops near the eastern city of Izyum and marking the biggest strategic gain Ukraine has made since the start of an offensive this week.

Photos from Russian and Ukrainian channels on Telegram showed Ukrainian soldiers holding the country’s flag in front of the city hall in Kupyansk, and Kremlin-loyal Russian military correspondents said Moscow’s forces had pulled back across the Oskil River to the eastern part of the city.

Ukraine’s control over the critical infrastructure of the city and the success of this week’s advance signal to Western backers the effectiveness of weapons the U.S. and Europe has given to Kyiv.

The Kupyansk rail and road hub located in the western half of the city was the last artery connecting Russia with thousands of troops on territory that represented the bulk of Russia’s gains in May and June. Ukraine’s control of the road network also threatens Russia’s hold on Izyum, a city Moscow had planned to use to launch further attacks on Ukrainian-controlled parts of the Donetsk region in the country’s east.

The U.K. Defense Ministry said Saturday that Izyum was becoming increasingly isolated. Analysts say Ukraine is aiming to encircle a pocket of Russian troops around Izyum east of the Oskil River.

“Izyum will soon be ours,” said a Ukrainian commander fighting near the city. [Continue reading…]