You have to remember those Republicans who have been calling more more aggressive actions are just doing that because they are either on the campaign trail or not in power or both and the consequences of what they are saying is small. As President they would have a lot of options to weigh up before committing to any actions and must accept any potential consequences from the resulting fallout. And as Kaz has correctly pointed out Obama has sharply escalated the 'war on terror'. Bush Jr may have had suspects kidnapped and interrogated using 'enhanced' interrogation techniques (i.e torture) but Obama doesn't even bother with that. He'd just not take any chances and send it in a drone strike which has killed way more civilians than suspected millitants.