Possibly naive question: How can Iran negotiate, when they know Trump won’t keep his word?

Maybe this has been well discussed already and if so I apologize. But it seems Iran can’t actually negotiate as long as Trump is president, because whatever terms they reach would be pointless. Right now the Iranians have the upper hand and aren’t in a rush to negotiate. But really— how can they negotiate, even if they want to?

Warren Buffett said “you can’t make a good deal with a bad person.”

Is it possible that this Iran war will be neither resolved nor escalated—that it just stalls out, and things stay the way they are for a year or more?