VIENNA, June 6 -- The drone came in less than a day after Ukraine signed the written guarantees. Five Russian sappers were wounded on the front line near Europe's largest nuclear power plant. And the International Atomic Energy Agency, which had personally secured those written pledges, said nothing.

That is the sequence of events Moscow laid out on Saturday, as Russia's Permanent Representative to international organizations in Vienna, Mikhail Ulyanov, accused Kyiv of breaking the terms of the sixth IAEA-brokered localized ceasefire around the Zaporizhzhia Nuclear Power Plant and charged the agency with a troubling indifference to the breach. The IAEA did not immediately respond to the allegation.

"The Ukrainian side provided written g...