Were that true I would expect to see on the maps evidence that Ukraine is winning the war currently. These maps are from March 17, April 15 and May 16.
On March 17, Ukraine was dire. Russia controlled all of northern Ukraine and was encircling the capital, Kyiv; all of southeastern Ukraine was under Russian control, although there were pockets of Ukrainian counteroffensives.
On April 15, Ukraine had reclaimed the territory around Kyiv and Russian forces withdrew. Russia tightened its grip on the east although there was significant fighting on the edges of Luhansk and Donetsk. In the southeast Russia reduced the pockets of Ukrainian counteroffensives to one area around Mykolaiv.
The map on May 16, yesterday, shows that Ukraine won the battle of Kharkiv and had reduced the area in the east under Russian control and was pressing Russian forces hard in the far east.
Comparing these maps we do indeed see evidence that Ukraine is winning the war; they have had success. Russia has abandoned the north central and the occupied territory in the far east has shrunk. Russia lost the battle for Kharkiv. However, Russia still controls a lot of Ukrainian territory in the far east and its position in the southeast has improved. The Azovstal steel mill was surrendered yesterday. "Ukraine can win this war" was the statement yesterday. Unless the Russian military suffers a sudden collapse it would appear to me that that day is far off.
