If evolution of man is real, why don't we get less intelligent?

I believe in the evolution of other animals, but not man. uming that man has evolved, man needed to get more intelligent in the past in order to protect himself against other animals, because man was the weakest of all and the only way he could survive was through developing intellectual capabalities, but nowadays this intellect is working against him (well, it has always worked against him if you think about it) politics, developing nuclear weapons, killing his own kind, etc, so isn't that to the benefit of our species to start a reverse process to become less intelligent?