Ukraine’s Counteroffensive Looms Large as Zelensky Addresses U.N.

President Volodymyr Zelensky will be addressing the U.N. General Assembly on Tuesday against the backdrop of Ukraine’s slow-moving and bloody counteroffensive to drive Russian forces from the country’s south and east.

When the campaign launched in June, officials had hoped Ukraine’s military could replicate the successes of last year and quickly retake large swaths of Russian-held territory.

Instead, Ukrainian forces initially made almost no progress. The pace of gains has increased in…