WEST HAVEN, Conn. (WTNH) — The attack that killed 13 American troops and dozens of civilians is what President Biden feared the most.

But, according to Dr. Matthew Schmidt, University of New Haven Professor of National Security, International Affairs and Political Science, it wasn’t a knee-jerk reaction to the withdrawal, nor was it a surprise.

“I spent many years teaching operational planning for the army,” he said. “We knew that something like this was almost certainly, not likely, almost certainly going to happen.”

Just because you may know an attack is coming, doesn’t mean you know when. Schmidt said everything was done to stop it from happening.

“That’s why our troops were outside the perimeter of the airport. To be part of the mix anticipating and preparing for this type of attack.”

As bad as it was, he said this was not a worst-case scenario.

“The worst-case scenario they were preparing for is direct attacks into and on the airport that would disrupt flights and operations. So, people have to understand that. It looks bad, but it is not as bad as what they were planning for.”

Since Aug. 1, the White House said more than 105,000 people have been evacuated. Schmidt credits the planning capabilities of our forces, our personnel and our allies.

In the end, Schmidt said we’re going to leave tens of thousands of Afghan allies behind, as well as 1,000 to 1,500 Americans who weren’t responding to what he called “repeated” attempts to communicate with them.

He said they didn’t reply. Perhaps for very good reasons.