[nabsgood]

The good: They've helped us end the cycle of wars between two major powers.

The bad: The danger that nuclear armageddon will be launched accidentally. The danger that nuclear weaponry will fall into the hands of terrorists who aren't affected by M.A.D. logic.

Overall I think that nukes, ICBMs, and MIRVs have been a good thing. They're scary enough that even the most strident war hawks are hesitant to use them. Even a nuclear attack launched by Al Quaeda probably wouldn't tip the balance, as an isolated nuclear attack with a most likely weak nuclear weapon wouldn't be as catastrophic as a large scale conventional war between the U.S. and China, China and India, China and U.S.S.R / Russia, or NATO and Warsaw pact would be / would have been.

The accidental nuclear holocaust is a freightening thought. We can't know for sure that nukes have been a positive good until we reach a point in time in which an accidental nuclear holocaust is rendered impossible.