The Iranian foreign minister, Mohammad Javad Zarif, vowed revenge against Israel on Monday morning, a day after a blackout at an Iranian nuclear enrichment site was attributed to an Israeli attack. Mr. Zarif’s comments highlight the risk of escalation in a years-long shadow war between Iran and Israel. They also threaten to overshadow efforts in Vienna to encourage Iran to reimpose limits on its nuclear program in exchange for the lifting of American sanctions. In a statement broadcast by Iranian state television, Mr. Zarif was quoted as saying: “The Zionists want to take revenge because of our progress in the way to lift sanctions.” He added, “But we will take our revenge from the Zionists,” according to the broadcast. Mr. Zarif’s reported comments followed a power failure on Sunday at the Natanz uranium enrichment site that Iranian officials attributed to Israeli sabotage. The Israeli government declined to […]