Who cares about terrorism. There are more people killed from lightning strikes than from terrorist attacks.
It is not about how many people are killed. States survive and propagate based on their ability to have stability so that they can effectively trade with other nations so a critical percentage
1 of their population prospers. If on 9-11 people decided to fly planes into Happy Chef Restaurant in Kadoka, SD then no one would give a damn. Flying a plane into the World Trade Center in New York City stopped market trading for days and shut down civilian United States air traffic. Imagine if people were blowing themselves up on buses, bridges, or police stations in every major US city at least once a month. It would shut down any ability for people to go out and make transactions and other nations would be able to take that opportunity to take over that wealth generating ability.
This is why the United States is pivoting its naval units to Asia to counter China's naval rise and oversee that international trade routes are not disturbed.
Obama knows he cannot keep his base and perpetuate the War on Terrorism (WOT) that Bush started. Bush thought this included massive military invasions and nation building. It might have worked but Bush underestimated the resources needed for this to happen. During that time a lot of people mentioned the success World War 2 (WW2) and the nation building after that. The difference between WW2 and the WOT is that the United States was involved in
total war, the complete mobilization of its resources to defeat the Axis Powers. This was not the case during the WOT. People went along with their daily lives and let the volunteer army try to achieve nation building. Obviously they failed.
Obama's strategy, and it is a very smart one politically, is to think of terrorist cells as cancer and to surgically remove that cancer through annihilation and/or fear. Annihilation comes from drone or special operation strikes. Fear comes from people that see that the United States military can't be everywhere at the same time but can be anywhere it wants to go. For this to work the national security industry must collect as much data as possible and strike any overseas target that may have any evidence of wanting to attack American interests.
The American people will only allow this level of surveillance if they don't feel safe, and if the goal of the government is to create stability so that enough people are happy that they don't overthrow the government then the government is stuck in a difficult situation. If the people don't feel safe then they will be unhappy and overthrow the government and if they do feel safe then they won't allow this level of surveillance and then the government cannot execute their surgical military operations.
1 I believe this critical percentage is related to the percent of unhappiness and the ease of access to efficient weapons and or voter turnout (democracies can overthrow their governments in elections, that is why they are more stable long term).