Why is Zelensky firing top leaders as Ukraine’s outlook improves?

KYIV — From the outside, this was shaping up as a strong year for wartime Ukraine.

Ukrainian drones are burning Russia’s refineries and starving occupied Crimea of fuel. Moscow’s summer offensive has stalled on most parts of the front, and Ukraine is taking back territory. In Washington, a president who spent last year berating Kyiv has warmed to it again.