After reading "Order of the phoenix" again, a theme which really comes across strong is that the "ministry" is trying to ignore that evil has cropped up again; with the head government guy even sending Umbridge to take over the school and prevent the teaching of practical defense against the bad guys. Very much like our situation with terrorists: some folks want us to just pretend that the bad guys mean us no harm.
The government officials, while denying that the threat existed, took actions that had the effect of giving the enemy aid and comfort.