The answer to this question is a little bit complicated. While it's true that Italians generally drink their coffee with less milk and sugar, it's not necessarily true that all Italian coffee is stronger than American coffee.
It really depends on the type of coffee you're drinking and how it's made. For example, a caffè latte is going to be weaker than a caffè macchiato because it has more milk.
However, if you're looking for a coffee that's going to give you a little bit more of a caffeine kick, it's always best to go for something that's less diluted like an espresso.
In the end, it really all comes down to personal preference. So, if you want a stronger coffee, go for something with less milk or sugar. If you want a weaker coffee, go for something with more milk or sugar. It's as simple as that!