A stunningly successful Ukrainian military counteroffensive has reclaimed thousands of miles of occupied territory in just two weeks while energizing the Ukrainian population, fomenting dissent in Russia and sending some of Moscow's worn-down forces scrambling in retreat.

Has the brutal war reached a turning point?

Most experts are expressing cautious optimism. John Kirby, the National Security Council's coordinator for strategic communications at the White House, at a briefing this week described the war as a "dynamic situation" and stressed that it was unpredictable.