There are many different points that he can be making. I hope it is not that Americans don't care when a terrorist blows himself up in Israel killing innocent men, women and children.
No, that's not the point, or at least not the point I'd make, and will make:
The amount of manpower and resources that America has expended in order to catch these shmucks is unbelievable. They literally have thousands of law enforcement officers coming Massachusetts. A large portion of the city of Boston has been completely shut down. Blacked out. Locked up tight.
This is from a single day, a single terrorist attack. The point is that as a result of this terrible tragedy Americans will have a *greater* appreciation for what Israel experiences not in a single day from a single terrorist attack, but from hundreds of attacks from thousands of terrorists.
If anything, we (myself included) have gained some much-needed perspective.