You guys keep forgetting the UN sanctions snapback deadline. If UN sanctions are reimposed, many Chinese and international companies outside the west are going to avoid trading with Iran. Going for negotiations until October is the only thing that makes sense. Even if the probability of sanctions being reimposed is very high, it still makes sense to try for the small chance of getting free from the UN sanctions. As the recent exchange has shown, Iran can survive a small scale war like this and even if another one happens before October it'll be fine. But if sanctions are reimposed, the costs might be even more severe than the war. You can thank the Russian and Chinese UN security council votes for making Iran utterly dependent on the European votes in the sanctions snapback process