Washington's defense has been playing well. But so has Seattle's. The Seahawks' defense has been below the radar giving up just 16.2 points in their last five games.
Seattle draws Washington minus Alex Smith and probably without Antonio Gibson. That means Washington is without its top quarterback and best running back. 
Russell Wilson versus Dwayne Haskins is a monster mismatch. I have far more faith in Wilson and the Seahawks' offense than in Washington's offense especially with Haskins under center.