Twelve years ago today the "Pearl Harbor" of the Long War took place in New York City, Washington, and a field in Pennsylvania. Sneak attacks on people who believed themselves at peace, resulting in thousands of deaths.
It is important that we do not forget what happened twelve years ago, or who was responsible. We also need to remember in the name of what cause the cowardly attacks were undertaken.
Two theater wars have happened since 9-11, in Iraq and Afghanistan, by way of striking back at the 9-11 perpetrators. Both involved nation-building, neither worked out well.
What is more effective are the various means by which we can bring death to jihadis: drone strikes, targeted assassinations, special warfare raids. Getting militant groups to attack each other, as in Syria, works too.