I always wondered if the idea of putting troops on the ground in Iran, leading to their inevitable slaughter would be a very convenient casus belli for using nukes.
Large troop losses of US "brave boys and girls", might just get the blood up again in those Americans who have cooled off on the idea of wars in foreign lands...of course, large troop losses could easily have the exact opposite effect and end up with Trump and his Murder,Inc. strung up on lampposts along Pennsylvania Avenue.