With this in mind we can ask ourselves, if it would have been better to have taken out Hitler early when he invaded Alsace-Lorraine, wouldn't also be better to take out ISIS before it takes over much more of the world? To do that, the USA may have to get involved much more so than it is now.
They have similarities in regards to how they repress knowledge and atrocities but as enemies Hitler and the Nazis are a different than ISIS. ISIS has factions all over the world so fighting a singular enemy will be difficult.
Long road ahead of us and unfortunately after taking out ISIS we will still have Boko Haram, al-Qaeda and Hamas
That's why I said the fight has to be against Islamic extremism, and ISIS is the dominant group. As for the Nazis, we (the Americans) had to fight them in North Africa before we took them on in Europe, so they were pretty spread out too.