I really don't fear that. America knows very well that Iran has lots of nuclear backup.
It looks like Iran has responded to the Zionists invading Lebanon, according to RT's interpretation.
I think the greatest development to fear is a Zionist nuclear strike on Iran if the damage to Tel Aviv becomes overwhelming for them. Iran is suspected of having greater convention weapons capability than the Zionists.
If the use a nuke then maybe everything will get very serious. But I think that's beyond America's red line on the Zionists' romp.