Japan has been stuck in a deflationary funk for decades. Europe, the US and other heavily indebted economies risk the same outcome if they follow the same path as Japan did after their credit bubble burst (ie. bank bailouts, ZIRP, endless QE).
Instead of allowing bad debts to be flushed out of the system so that a sustainable recovery could commence, govts, regulators and central bankers have created a far larger and prolonged debt problem through their actions. Actions that unfortunately are very likely to soon lead to devastating results.
No body wants to see a deflationary collapse, but everybody should prepare for one.