New Delhi, June 10 -- MOSCOW - The negotiators have not left the table. That may be the only reason the word "irreparable" still feels like a warning rather than a verdict.

Maria Zakharova, the Russian Foreign Ministry spokeswoman, told reporters at a Wednesday briefing in Moscow that any ground operation against Iran would represent "a further escalation of tension, fraught with literally irreparable consequences" for every party involved, and for the stability of the region and the world beyond it. She acknowledged, in the same breath, that an active negotiation process remains underway. The situation, she added, remains "extremely unstable."

The word she chose marks a threshold in Moscow's public language on the Iran conflict that ha...