Of all the problems with fiat currency, the most basic is that it empowers the dark side of human nature. We're potentially good but infinitely corruptible, and giving an unlimited monetary printing press to a government or group of banks is guaranteed to produce a dystopia of ever-greater debt and more centralized control, until the only remaining choice is between deflationary collapse or runaway inflation. The people in charge at that point are in a box with no painless exit.

Prudent Bear's Doug Noland describes the shape of today's box in his latest Credit Bubble Bulletin:

Right here we can identify a key systemic weak link: Market pricing and bullish perceptions have diverged profoundly both from underlying risk (i.e. Credit, liquidity, market pricing, policymaking, etc.) and diminishing Real economy prospects. And now, with a full-fledged securities market mania inflating the Financial Sphere, it has become impossible for central banks to narrow the gap between the financial Bubbles and (disinflationary) real economies. More stimulus measures only feed the Bubble and prolong parabolic (“Terminal Phase”) increases in systemic risk. In short, central bankers these days are trapped in policies that primarily inflate risk. The old reflation game no longer works.

In other words, most real economies (jobs, production of physical goods, government budgets) around the world are back in (or have never left) recession, for which the traditional response is monetary and fiscal stimulus — that is, lower interest rates and bigger government deficits. Meanwhile, the financial markets are roaring, which normally calls for tighter money and reduced deficits to keep the bubbles from destabilizing.

Both problems are emerging simultaneously and the traditional response to one will make the other much, much worse. Some more specifics from Noland: