Probably the only thing that was correctly said to equalize physical confrontation was invented by a man called Samuel Colt. The Peacemaker
leveled the playing field and turned it into a cemetery.
While the techniques of Aikido can be used in self-defense, I don't believe that to be it's true nature. Aikido can brings its practioners into harmony with themselves, others and ultimately with the universe. This appears to be the core teaching of K. Tohei, K. Ueshiba and their teacher Morihei Ueshiba.
This is the same ultimate goal that Tai Chi, Yoga and many of the contemplative arts from Asia have.
Life doesn't come with a guarantee. Even Superman had to fear Kryptonite.