Nuclear diplomacy derails as Israel’s Airstrikes on Iran Shatter U.S. Nuclear Talks: Diplomacy in Crisis. The sixth round of indirect U.S.-Iran nuclear talks, which was scheduled for Sunday in Muscat, Oman, has been abruptly canceled following a massive escalation between Israel and Iran. The breakdown in diplomacy comes after Israel launched hundreds of airstrikes inside Iran, targeting military and nuclear infrastructure. Iran has responded with missile attacks on Israeli cities, heightening fears of an all-out regional war in the Middle East.