If you ask which of the scenarios I think is most dangerous, though, I will give a different answer. In that form of the question, I regard a nuclear attack, terrorist-generated or otherwise, as the most threatening combination of likelihood and long-term damage to modern life today.
John L. CastiSystem theorists know that it's easy to couple simple-to-understand systems into a "super system" that's capable of displaying behavioral modes that cannot be seen in any of its constituent parts. This is the process called "emergence."
John L. CastiTrying to solve the problem by creating more debt is analogous to trying to stop being an alcoholic by going on a bender down at the corner bar.
John L. CastiA good analogy is stretching a rubber band. You can stretch and stretch and even feel the tension increase in the muscles in your hands and arms as the gap from one end of the band to the other widens. But at some point you reach the limits of elasticity of the band and it snaps. The same thing happens with human systems.
John L. Casti