Yes, we do practice attack in Aikido. We attack so that our partner can pactices their defense. To help our partner understand the principles and energy of an attacker. The understanding will help the nage learn and improves the defensive strategy that nullifies all attacks eventually.
The principle of attack in Aikido is not to score a point or bring home a medal. we help our partner reflect themselves. We can all wax lyrical about being at peace, or being peaceful, but all that gets stuck when our uke stresses us with attacks. we lost our composure because our reflection of ourselves is actually a figment of our imagination.
So when I attack in Aikido, I put my nage’s self concept in an acid test. the close you are to yourself, the better you perform under duress. because in reality, peace and duress is but imposters of reality.