That initial talks between Iran and the United States in Oman were described by the US side as positive and constructive and by Iran as respectful and between equals is some good news during a highly uncertain period in international affairs. The talks are to continue next week. Their subject matter, Iran’s nuclear arms programme and sanctions against that state, are however complex and not fully resolvable in the two month timespan demanded by President Trump. Interestingly, both sides have strong incentives to reach an agreement. Trump withdrew the US from the multilateral agreement reached with Iran in 2018. Since...