Because they never knew that Tatsuya's magic is the opposite of Katsugo's magic. Since Tatsuya's magic still remain a secret.
The question that was asked since the School arc or the beginning:
Which will win, the spear that can pierce through anything or the shield that can block anything?
Most likely notified by edward clark as part of his scheme to get rid off tatsuya. The guy do have god complex and think that anything that his country and by proxy him, is the only power that has the right to control the world.