Ukraine’s Stalled Counteroffensive, Explained

Ukraine and its NATO allies hoped this spring’s long-awaited counteroffensive against Russia would resemble the success of counterattacks in the Kharkiv and Kherson regions last year. But advancing Ukrainian forces quickly came up against dug-in Russian forces and have since made incremental gains at enormous costs.
Russian President Vladimir Putin’s declaration on Sunday that the operation had “failed” is one thing—but even Ukrainian President Volodymyr Zelensky admits the campaign hasn’t gone entirely to plan.
What are advancing Ukrainian forces up against?
Ukrainian military planners spent months preparing for the counteroffensive. So did Russian forces. At the southern and eastern frontlines, retreating Russian troops took high ground positions, built barriers and bunkers, deployed heavy artillery, and laid dense minefields.