Should humanity construct an interstellar weapon of mass destruction and retaliation? I think we should.

Consider the following. Humanity could construct a missile that would have a thousand megatons of nuclear power and filled with cobolt. This would be enough to destroy any planet supporting carbon life.

This missile would then be parked in orbit around Pluto or anywhere in the System. If aliens were to attack us it would be sent towards their system. Over decades it would gradually pick up speed and would eventually reach few % c. It would impact the alien home planet with enough kinetic power and radiation to wipe out all life.

With this, humanity could intimidate and threaten ayylmaos to work with us, instead of against us.

Why are we wasting money on ISS or Mars colonization when this should be priority number one?