A sucker punch is nearly impossible to catch.
The US is ranked overwhelmingly first in military power on this planet. Iran, fourteenth.
Are you suggesting that the attack not be answered?
Are you suggesting that an attack on Iran won't be answered?
No matter the rank of US military power on the planet there'll still be flying thousands of missiles in retaliation from Iran and all its proxies in the region.
USA and its allies can't stomach the consequences, the world and Iran knows this.