How is the US 12 days behind? Where does that number come from? The first Italian case was a month after the first US case.
Italy has an older population to start with. I don't think the US will remotely reach the chaos we are seeing in Italy.
Land size if Italy is 116,347 mi², land size of US is 3.797 million mi²
I don't think it's fair to make any assumptions from those infection numbers when the two countries are vastly different.