You can't use military force against a sovereign nation just to send them or others a message.
Attacking Qatar would be a terrible mistake in any case. As stupid as Saddam attacking Kuwait.
We must first know if the Americans had informed the Qataris or not. Meanwhile, as I said before, no Iranian authority has claimed that Qatar is responsible for this. If Qatar was indeed involved in this, the best way to respond to it is by attacking one of their tankers in a sabotage operation, or something along those lines.