I didn’t say no doubt the speedboats would be successful in a naval conflict with the US. I just did a comparison between the speedboats and warship in Persian Gulf. I think according to Persian Gulf geographical conditions, using speedboats is more practical for Iran than using warships. Those are cheap, small and a lot, some of them has a speed about 65-70 Nat, some of them are equipped to 35km and 15-20km rang cruise missiles (Nasr 1 and Kosar), some of them are equipped to air defense system, some of them are unmanned, they discovered by radar hardly and the most important thing is that all of those have been made in Iran.
In the Persian Gulf where the average deep is about 50 m and the widest part is about 180 km and with limited shipping zones that can be more restricted by mines, Using small speedboats or midgets is more practical than big warships. Admiral Fox talks were about these threats.
And it is why when the likelihood of conflict be increased, the US transfers their Aircraft carrier quickly to the India Ocean and come back with Franc and Britain warships. The last transfer was when Iran was preparing to do a maneuver around the Hormuz Strait.