Why is radioactive decay important enough to be a fundamental force?

[bh258]

Im not sure if this is a bad question but what is radioactive decay and why is it so important they needed a new force to explain it. It might just be me but compared to the other three forces its existence seems miniscule. (just turned 14 so am still in stupid integrated science for eighth graders)

 

[mathman]

The weak nuclear force is needed for theory to explain beta decay - the other forces don't. It happens to be stronger than gravity, but that is besides the point.