“If they did make it onto the base, and if they managed to fire weapons and slaughter innocent and unarmed military personnel - it would NOT be a terrorist incident.”
Attacks against a military target are generally NOT considered terrorism. Attack a nightclub full of civilians = terrorism, attack a military base full of soldiers = combat operation.
While he might not have understood the radical Muslim mindset, George W. Bush knew how to send a military message. "We'll see your two destroyed buildings and raise you two removed governments friendly to your cause. Want to keep playing?" There was a reason that the U.S. was generally left alone during the Bush years. He spoke a language that the terrorists understood.
For every U.S. victim of these attacks, I suggest that we take out one terrorist training base. No warnings, no permissions asked, we just respond and it doesn't matter whether the base is in the mountains of Pakistan, a remote island in the Philippines, the deserts of Yemen. While the governments would officially squawk about this, there would be significant moderate elements in the country which would be glad to see these groups and their training camps removed from their country.
Perhaps then it would be a quasi kinetic military mishap?