Where is the international economy heading to?

The manufacturing sector stock is going on depriciating in Japan. The change in exchange rate is not understandable these days, either. What will go on? Isn't the short term investment money related with these changes? The crisis in international economy is often caused by those investors.

They say the economic crisis in Eu is responsible for these changes. The crises in Italy or in Spain seem to have occurred suddenly. Of course, I know there is a structural problem in Eu countries, the southern countries always being in deficits of national finance. But the appearnce of the crises in some of those countries seems to be too abrupt. I am afraid short term investors with much money are artificially causing this crisis.

Some people say that the japanese economy would be the next target for those investors. The fundamentals are not very promising especially from long range of perspective. The debt of the nation is amounted up to 260% of GDP, which is comparable only to that during WW2. We, the people, are purchasing the national bonds to compensate this big amount of debts. But some some minute manipulation by those investors may cause a drastic change toward the drop of  JPY and of the price of national bonds.

Any drastic changes would harm the usual people who cound never do with such changes. Fairness in the international economy is really needed to avoid such catastrophic changes but to sustain slow and steady growth of economy in every country.