That would be the hydrogen bomb. If we created a sizeable MIRV of cobalt bombs and pointed them at Jerusalem on an automated system that tracked the rate of violent death, suddenly all the religious types would get really polite.

(Obviously this is a supervillain example. we're considering alternative vectors towards peace and humanitarian aid in the holy land before holding it hostage. We're also running out of saner ideas.)

(Also, the Soviet Union did consider a doomsday device a la Dr. Strangelove as a cold war nuclear deterrent before the politburo decided it would never authorize a retalitory strike for sake of the species and moved on to Мирное сосуществование. Nearly eighty years without a nuclear war shows us even religious fanatics and madmen don't want to extinct the human species. Their heart's not in it.)

The problem is, smaller interests can't get the bomb yet. It takes too much complex industry to make. As a result, we still have huge swaths of powerless population to be bullied, enslaved and exploited.

Once the superweapon made from fir wood, Indian ocean tuna, granite and parafin becomes public we'll have to negotiate with even the smallest faction and arrange for the welfare and contentment of everyone... that is if we survive the intermediary tensions. Our plutocrats may choose extinction over giving up their power.