But if there really is live down there, how do you then explain to them that you just dropped some nuclear waste into their ocean?

"We have reasons to believe you posses weapons of mass destruction"

Worked fine with all the depleted uranium dropped on Iraq.

Europeans (pun intended) could be much better equipped to retaliate than Iraqis.

It has definitely been suggested: http://en.wikipedia.org/wiki/Cryobot http://www.jpl.nasa.gov/releases/2002/release_2002_6.html